diff --git a/CHANGELOG.md b/CHANGELOG.md
index f132a40c..76988274 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,6 +21,12 @@ Deprecated API's
 * `Module::with_capacity` is deprecated.
 * The internal method `Engine::eval_statements_raw` is deprecated.
 
+Speed improvements
+------------------
+
+* The functions registration mechanism is revamped to take advantage of constant generics, among others.
+* This yields a 20% speed improvements on certain real-life, function-call-heavy workloads.
+
 Net features
 ------------
 
diff --git a/Cargo.toml b/Cargo.toml
index 14fb9603..d56384f9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,7 +23,7 @@ ahash = { version = "0.8.2", default-features = false, features = ["compile-time
 num-traits = { version = "0.2", default-features = false }
 bitflags = { version = "1", default-features = false }
 smartstring = { version = "1", default-features = false }
-rhai_codegen = { version = "1.4.1", path = "codegen", default-features = false }
+rhai_codegen = { version = "1.5.0", path = "codegen", default-features = false }
 
 no-std-compat = { version = "0.4", default-features = false, features = ["alloc"], optional = true }
 libm = { version = "0.2", default-features = false, optional = true }
diff --git a/codegen/Cargo.toml b/codegen/Cargo.toml
index 6364db5c..8a1495c9 100644
--- a/codegen/Cargo.toml
+++ b/codegen/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "rhai_codegen"
-version = "1.4.4"
+version = "1.5.0"
 edition = "2018"
 resolver = "2"
 authors = ["jhwgh1968", "Stephen Chung"]
@@ -24,5 +24,5 @@ syn = { version = "1.0", features = ["full", "parsing", "printing", "proc-macro"
 quote = "1"
 
 [dev-dependencies]
-rhai = { path = "..", version = "1.11", features = ["metadata"] }
+rhai = { path = "..", version = "1.12", features = ["metadata"] }
 trybuild = "1"
diff --git a/codegen/src/function.rs b/codegen/src/function.rs
index aaa07df5..27ec31c1 100644
--- a/codegen/src/function.rs
+++ b/codegen/src/function.rs
@@ -674,6 +674,7 @@ impl ExportedFn {
         let arg_count = self.arg_count();
         let is_method_call = self.mutable_receiver();
         let is_pure = !self.mutable_receiver() || self.params().pure.is_some();
+        let pass_context = self.pass_context;
 
         let mut unpack_statements = Vec::new();
         let mut unpack_exprs = Vec::new();
@@ -689,7 +690,7 @@ impl ExportedFn {
         let skip_first_arg;
 
         if self.pass_context {
-            unpack_exprs.push(syn::parse2::<syn::Expr>(quote! { context }).unwrap());
+            unpack_exprs.push(syn::parse2::<syn::Expr>(quote! { context.unwrap() }).unwrap());
         }
 
         // Handle the first argument separately if the function has a "method like" receiver
@@ -860,13 +861,14 @@ impl ExportedFn {
             #(#cfg_attrs)*
             impl PluginFunction for #type_name {
                 #[inline(always)]
-                fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                     #(#unpack_statements)*
                     #return_expr
                 }
 
                 #[inline(always)] fn is_method_call(&self) -> bool { #is_method_call }
                 #[inline(always)] fn is_pure(&self) -> bool { #is_pure }
+                #[inline(always)] fn has_context(&self) -> bool { #pass_context }
             }
         }
     }
diff --git a/codegen/src/test/function.rs b/codegen/src/test/function.rs
index 05d99130..0af46110 100644
--- a/codegen/src/test/function.rs
+++ b/codegen/src/test/function.rs
@@ -280,12 +280,13 @@ mod generate_tests {
                     #[inline(always)] pub fn param_types() -> [TypeId; 0usize] { [] }
                 }
                 impl PluginFunction for Token {
-                    #[inline(always)] fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    #[inline(always)] fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         Ok(Dynamic::from(do_nothing()))
                     }
 
                     #[inline(always)] fn is_method_call(&self) -> bool { false }
                     #[inline(always)] fn is_pure(&self) -> bool { true }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
                 #[allow(unused)]
                 #[doc(hidden)]
@@ -318,13 +319,14 @@ mod generate_tests {
                 }
                 impl PluginFunction for Token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg0 = mem::take(args[0usize]).cast::<usize>();
                         Ok(Dynamic::from(do_something(arg0)))
                     }
 
                     #[inline(always)] fn is_method_call(&self) -> bool { false }
                     #[inline(always)] fn is_pure(&self) -> bool { true }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
                 #[allow(unused)]
                 #[doc(hidden)]
@@ -357,13 +359,14 @@ mod generate_tests {
                 }
                 impl PluginFunction for Token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg0 = mem::take(args[0usize]).cast::<usize>();
-                        Ok(Dynamic::from(do_something(context, arg0)))
+                        Ok(Dynamic::from(do_something(context.unwrap(), arg0)))
                     }
 
                     #[inline(always)] fn is_method_call(&self) -> bool { false }
                     #[inline(always)] fn is_pure(&self) -> bool { true }
+                    #[inline(always)] fn has_context(&self) -> bool { true }
                 }
                 #[allow(unused)]
                 #[doc(hidden)]
@@ -399,12 +402,13 @@ mod generate_tests {
                 }
                 impl PluginFunction for Token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         Ok(Dynamic::from(return_dynamic()))
                     }
 
                     #[inline(always)] fn is_method_call(&self) -> bool { false }
                     #[inline(always)] fn is_pure(&self) -> bool { true }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
                 #[allow(unused)]
                 #[doc(hidden)]
@@ -432,13 +436,14 @@ mod generate_tests {
             }
             impl PluginFunction for TestStruct {
                 #[inline(always)]
-                fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                     let arg0 = mem::take(args[0usize]).cast::<usize>();
                     Ok(Dynamic::from(do_something(arg0)))
                 }
 
                 #[inline(always)] fn is_method_call(&self) -> bool { false }
                 #[inline(always)] fn is_pure(&self) -> bool { true }
+                #[inline(always)] fn has_context(&self) -> bool { false }
             }
         };
 
@@ -465,7 +470,7 @@ mod generate_tests {
                 }
                 impl PluginFunction for Token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg0 = mem::take(args[0usize]).cast::<usize>();
                         let arg1 = mem::take(args[1usize]).cast::<usize>();
                         Ok(Dynamic::from(add_together(arg0, arg1)))
@@ -473,6 +478,7 @@ mod generate_tests {
 
                     #[inline(always)] fn is_method_call(&self) -> bool { false }
                     #[inline(always)] fn is_pure(&self) -> bool { true }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
                 #[allow(unused)]
                 #[doc(hidden)]
@@ -505,7 +511,7 @@ mod generate_tests {
                 }
                 impl PluginFunction for Token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg1 = mem::take(args[1usize]).cast::<usize>();
                         let arg0 = &mut args[0usize].write_lock::<usize>().unwrap();
                         Ok(Dynamic::from(increment(arg0, arg1)))
@@ -513,6 +519,7 @@ mod generate_tests {
 
                     #[inline(always)] fn is_method_call(&self) -> bool { true }
                     #[inline(always)] fn is_pure(&self) -> bool { false }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
                 #[allow(unused)]
                 #[doc(hidden)]
@@ -546,13 +553,14 @@ mod generate_tests {
                 }
                 impl PluginFunction for Token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg0 = mem::take(args[0usize]).into_immutable_string().unwrap();
                         Ok(Dynamic::from(special_print(&arg0)))
                     }
 
                     #[inline(always)] fn is_method_call(&self) -> bool { false }
                     #[inline(always)] fn is_pure(&self) -> bool { true }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
                 #[allow(unused)]
                 #[doc(hidden)]
diff --git a/codegen/src/test/module.rs b/codegen/src/test/module.rs
index 3575d2c4..f333e23b 100644
--- a/codegen/src/test/module.rs
+++ b/codegen/src/test/module.rs
@@ -386,12 +386,13 @@ mod generate_tests {
                 }
                 impl PluginFunction for get_mystic_number_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         Ok(Dynamic::from(get_mystic_number()))
                     }
 
                     #[inline(always)] fn is_method_call(&self) -> bool { false }
                     #[inline(always)] fn is_pure(&self) -> bool { true }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -474,12 +475,13 @@ mod generate_tests {
                 }
                 impl PluginFunction for get_mystic_number_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         Ok(Dynamic::from(get_mystic_number()))
                     }
 
                     #[inline(always)] fn is_method_call(&self) -> bool { false }
                     #[inline(always)] fn is_pure(&self) -> bool { true }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -532,13 +534,14 @@ mod generate_tests {
                 }
                 impl PluginFunction for add_one_to_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg0 = mem::take(args[0usize]).cast::<INT>();
                         Ok(Dynamic::from(add_one_to(arg0)))
                     }
 
                     #[inline(always)] fn is_method_call(&self) -> bool { false }
                     #[inline(always)] fn is_pure(&self) -> bool { true }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -590,13 +593,14 @@ mod generate_tests {
                 }
                 impl PluginFunction for add_one_to_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg0 = mem::take(args[0usize]).cast::<INT>();
                         Ok(Dynamic::from(add_one_to(arg0)))
                     }
 
                     #[inline(always)] fn is_method_call(&self) -> bool { false }
                     #[inline(always)] fn is_pure(&self) -> bool { true }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -662,13 +666,14 @@ mod generate_tests {
                 }
                 impl PluginFunction for add_one_to_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg0 = mem::take(args[0usize]).cast::<INT>();
                         Ok(Dynamic::from(add_one_to(arg0)))
                     }
 
                     #[inline(always)] fn is_method_call(&self) -> bool { false }
                     #[inline(always)] fn is_pure(&self) -> bool { true }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
 
                 #[allow(non_camel_case_types)]
@@ -681,7 +686,7 @@ mod generate_tests {
                 }
                 impl PluginFunction for add_n_to_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg0 = mem::take(args[0usize]).cast::<INT>();
                         let arg1 = mem::take(args[1usize]).cast::<INT>();
                         Ok(Dynamic::from(add_n_to(arg0, arg1)))
@@ -689,6 +694,7 @@ mod generate_tests {
 
                     #[inline(always)] fn is_method_call(&self) -> bool { false }
                     #[inline(always)] fn is_pure(&self) -> bool { true }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -740,7 +746,7 @@ mod generate_tests {
                 }
                 impl PluginFunction for add_together_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg0 = mem::take(args[0usize]).cast::<INT>();
                         let arg1 = mem::take(args[1usize]).cast::<INT>();
                         Ok(Dynamic::from(add_together(arg0, arg1)))
@@ -748,6 +754,7 @@ mod generate_tests {
 
                     #[inline(always)] fn is_method_call(&self) -> bool { false }
                     #[inline(always)] fn is_pure(&self) -> bool { true }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -806,7 +813,7 @@ mod generate_tests {
                 }
                 impl PluginFunction for add_together_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg0 = mem::take(args[0usize]).cast::<INT>();
                         let arg1 = mem::take(args[1usize]).cast::<INT>();
                         Ok(Dynamic::from(add_together(arg0, arg1)))
@@ -814,6 +821,7 @@ mod generate_tests {
 
                     #[inline(always)] fn is_method_call(&self) -> bool { false }
                     #[inline(always)] fn is_pure(&self) -> bool { true }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -882,13 +890,14 @@ mod generate_tests {
                 }
                 impl PluginFunction for get_mystic_number_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg0 = &mut args[0usize].write_lock::<Hello>().unwrap();
                         Ok(Dynamic::from(get_mystic_number(arg0)))
                     }
 
                     #[inline(always)] fn is_method_call(&self) -> bool { true }
                     #[inline(always)] fn is_pure(&self) -> bool { false }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -1092,12 +1101,13 @@ mod generate_tests {
                 }
                 impl PluginFunction for get_mystic_number_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         Ok(Dynamic::from(get_mystic_number()))
                     }
 
                     #[inline(always)] fn is_method_call(&self) -> bool { false }
                     #[inline(always)] fn is_pure(&self) -> bool { true }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -1182,13 +1192,14 @@ mod generate_tests {
                 }
                 impl PluginFunction for print_out_to_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg0 = mem::take(args[0usize]).into_immutable_string().unwrap();
                         Ok(Dynamic::from(print_out_to(&arg0)))
                     }
 
                     #[inline(always)] fn is_method_call(&self) -> bool { false }
                     #[inline(always)] fn is_pure(&self) -> bool { true }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -1240,13 +1251,14 @@ mod generate_tests {
                 }
                 impl PluginFunction for print_out_to_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg0 = mem::take(args[0usize]).into_string().unwrap();
                         Ok(Dynamic::from(print_out_to(arg0)))
                     }
 
                     #[inline(always)] fn is_method_call(&self) -> bool { false }
                     #[inline(always)] fn is_pure(&self) -> bool { true }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -1299,7 +1311,7 @@ mod generate_tests {
                 }
                 impl PluginFunction for foo_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg1 = mem::take(args[1usize]).cast::<INT>();
                         let arg0 = &mut args[0usize].write_lock::<FLOAT>().unwrap();
                         Ok(Dynamic::from(foo(arg0, arg1)))
@@ -1307,6 +1319,7 @@ mod generate_tests {
 
                     #[inline(always)] fn is_method_call(&self) -> bool { true }
                     #[inline(always)] fn is_pure(&self) -> bool { true }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -1358,13 +1371,14 @@ mod generate_tests {
                 }
                 impl PluginFunction for increment_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg0 = &mut args[0usize].write_lock::<FLOAT>().unwrap();
                         Ok(Dynamic::from(increment(arg0)))
                     }
 
                     #[inline(always)] fn is_method_call(&self) -> bool { true }
                     #[inline(always)] fn is_pure(&self) -> bool { false }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -1419,13 +1433,14 @@ mod generate_tests {
                     }
                     impl PluginFunction for increment_token {
                         #[inline(always)]
-                        fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                        fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                             let arg0 = &mut args[0usize].write_lock::<FLOAT>().unwrap();
                             Ok(Dynamic::from(increment(arg0)))
                         }
 
                         #[inline(always)] fn is_method_call(&self) -> bool { true }
                         #[inline(always)] fn is_pure(&self) -> bool { false }
+                        #[inline(always)] fn has_context(&self) -> bool { false }
                     }
                 }
                 #[allow(unused_imports)]
@@ -1503,13 +1518,14 @@ mod generate_tests {
                     }
                     impl PluginFunction for increment_token {
                         #[inline(always)]
-                        fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                        fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                             let arg0 = &mut args[0usize].write_lock::<FLOAT>().unwrap();
                             Ok(Dynamic::from(increment(arg0)))
                         }
 
                         #[inline(always)] fn is_method_call(&self) -> bool { true }
                         #[inline(always)] fn is_pure(&self) -> bool { false }
+                        #[inline(always)] fn has_context(&self) -> bool { false }
                     }
                 }
                 #[allow(unused_imports)]
@@ -1588,13 +1604,14 @@ mod generate_tests {
                 }
                 impl PluginFunction for int_foo_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg0 = &mut args[0usize].write_lock::<u64>().unwrap();
                         Ok(Dynamic::from(int_foo(arg0)))
                     }
 
                     #[inline(always)] fn is_method_call(&self) -> bool { true }
                     #[inline(always)] fn is_pure(&self) -> bool { false }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -1650,13 +1667,14 @@ mod generate_tests {
                 }
                 impl PluginFunction for int_foo_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg0 = &mut args[0usize].write_lock::<u64>().unwrap();
                         Ok(Dynamic::from(int_foo(arg0)))
                     }
 
                     #[inline(always)] fn is_method_call(&self) -> bool { true }
                     #[inline(always)] fn is_pure(&self) -> bool { false }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -1709,7 +1727,7 @@ mod generate_tests {
                 }
                 impl PluginFunction for int_foo_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg1 = mem::take(args[1usize]).cast::<u64>();
                         let arg0 = &mut args[0usize].write_lock::<u64>().unwrap();
                         Ok(Dynamic::from(int_foo(arg0, arg1)))
@@ -1717,6 +1735,7 @@ mod generate_tests {
 
                     #[inline(always)] fn is_method_call(&self) -> bool { true }
                     #[inline(always)] fn is_pure(&self) -> bool { false }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -1772,7 +1791,7 @@ mod generate_tests {
                 }
                 impl PluginFunction for int_foo_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg1 = mem::take(args[1usize]).cast::<u64>();
                         let arg0 = &mut args[0usize].write_lock::<u64>().unwrap();
                         Ok(Dynamic::from(int_foo(arg0, arg1)))
@@ -1780,6 +1799,7 @@ mod generate_tests {
 
                     #[inline(always)] fn is_method_call(&self) -> bool { true }
                     #[inline(always)] fn is_pure(&self) -> bool { false }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -1832,7 +1852,7 @@ mod generate_tests {
                 }
                 impl PluginFunction for get_by_index_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg1 = mem::take(args[1usize]).cast::<u64>();
                         let arg0 = &mut args[0usize].write_lock::<MyCollection>().unwrap();
                         Ok(Dynamic::from(get_by_index(arg0, arg1)))
@@ -1840,6 +1860,7 @@ mod generate_tests {
 
                     #[inline(always)] fn is_method_call(&self) -> bool { true }
                     #[inline(always)] fn is_pure(&self) -> bool { false }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -1900,7 +1921,7 @@ mod generate_tests {
                 #[cfg(hello)]
                 impl PluginFunction for get_by_index_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg1 = mem::take(args[1usize]).cast::<u64>();
                         let arg0 = &mut args[0usize].write_lock::<MyCollection>().unwrap();
                         Ok(Dynamic::from(get_by_index(arg0, arg1)))
@@ -1908,6 +1929,7 @@ mod generate_tests {
 
                     #[inline(always)] fn is_method_call(&self) -> bool { true }
                     #[inline(always)] fn is_pure(&self) -> bool { false }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -1963,7 +1985,7 @@ mod generate_tests {
                 }
                 impl PluginFunction for get_by_index_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg1 = mem::take(args[1usize]).cast::<u64>();
                         let arg0 = &mut args[0usize].write_lock::<MyCollection>().unwrap();
                         Ok(Dynamic::from(get_by_index(arg0, arg1)))
@@ -1971,6 +1993,7 @@ mod generate_tests {
 
                     #[inline(always)] fn is_method_call(&self) -> bool { true }
                     #[inline(always)] fn is_pure(&self) -> bool { false }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -2023,7 +2046,7 @@ mod generate_tests {
                 }
                 impl PluginFunction for set_by_index_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg1 = mem::take(args[1usize]).cast::<u64>();
                         let arg2 = mem::take(args[2usize]).cast::<FLOAT>();
                         let arg0 = &mut args[0usize].write_lock::<MyCollection>().unwrap();
@@ -2032,6 +2055,7 @@ mod generate_tests {
 
                     #[inline(always)] fn is_method_call(&self) -> bool { true }
                     #[inline(always)] fn is_pure(&self) -> bool { false }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
@@ -2087,7 +2111,7 @@ mod generate_tests {
                 }
                 impl PluginFunction for set_by_index_token {
                     #[inline(always)]
-                    fn call(&self, context: NativeCallContext, args: &mut [&mut Dynamic]) -> RhaiResult {
+                    fn call(&self, context: Option<NativeCallContext>, args: &mut [&mut Dynamic]) -> RhaiResult {
                         let arg1 = mem::take(args[1usize]).cast::<u64>();
                         let arg2 = mem::take(args[2usize]).cast::<FLOAT>();
                         let arg0 = &mut args[0usize].write_lock::<MyCollection>().unwrap();
@@ -2096,6 +2120,7 @@ mod generate_tests {
 
                     #[inline(always)] fn is_method_call(&self) -> bool { true }
                     #[inline(always)] fn is_pure(&self) -> bool { false }
+                    #[inline(always)] fn has_context(&self) -> bool { false }
                 }
             }
         };
diff --git a/src/func/call.rs b/src/func/call.rs
index 91522cad..e5f5adc9 100644
--- a/src/func/call.rs
+++ b/src/func/call.rs
@@ -401,19 +401,19 @@ impl Engine {
             let is_method = func.is_method();
             let src = source.as_ref().map(|s| s.as_str());
 
+            let context = if func.has_context() {
+                Some((self, name, src, &*global, pos).into())
+            } else {
+                None
+            };
+
             let mut _result = if let Some(f) = func.get_plugin_fn() {
                 if !f.is_pure() && !args.is_empty() && args[0].is_read_only() {
                     Err(ERR::ErrorNonPureMethodCallOnConstant(name.to_string(), pos).into())
                 } else {
-                    let context = (self, name, src, &*global, pos).into();
                     f.call(context, args)
                 }
             } else if let Some(f) = func.get_native_fn() {
-                let context = if func.has_context() {
-                    Some((self, name, src, &*global, pos).into())
-                } else {
-                    None
-                };
                 f(context, args)
             } else {
                 unreachable!();
@@ -1390,8 +1390,12 @@ impl Engine {
             }
 
             Some(f) if f.is_plugin_fn() => {
-                let context = (self, fn_name, module.id(), &*global, pos).into();
                 let f = f.get_plugin_fn().expect("plugin function");
+                let context = if f.has_context() {
+                    Some((self, fn_name, module.id(), &*global, pos).into())
+                } else {
+                    None
+                };
                 if !f.is_pure() && !args.is_empty() && args[0].is_read_only() {
                     Err(ERR::ErrorNonPureMethodCallOnConstant(fn_name.to_string(), pos).into())
                 } else {
diff --git a/src/func/callable_function.rs b/src/func/callable_function.rs
index cde5effa..d7ed45bf 100644
--- a/src/func/callable_function.rs
+++ b/src/func/callable_function.rs
@@ -142,7 +142,8 @@ impl CallableFunction {
     pub fn has_context(&self) -> bool {
         match self {
             Self::Pure(.., ctx) | Self::Method(.., ctx) => *ctx,
-            Self::Plugin(..) | Self::Iterator(..) => false,
+            Self::Plugin(f) => f.has_context(),
+            Self::Iterator(..) => false,
             #[cfg(not(feature = "no_function"))]
             Self::Script(..) => false,
         }
diff --git a/src/func/plugin.rs b/src/func/plugin.rs
index b4a9b9d0..831e6919 100644
--- a/src/func/plugin.rs
+++ b/src/func/plugin.rs
@@ -24,12 +24,16 @@ pub use rhai_codegen::{export_fn, register_exported_fn};
 /// Use the `#[export_module]` and `#[export_fn]` procedural attributes instead.
 pub trait PluginFunction {
     /// Call the plugin function with the arguments provided.
-    fn call(&self, context: NativeCallContext, args: &mut FnCallArgs) -> RhaiResult;
+    fn call(&self, context: Option<NativeCallContext>, args: &mut FnCallArgs) -> RhaiResult;
 
     /// Is this plugin function a method?
     #[must_use]
     fn is_method_call(&self) -> bool;
 
+    /// Does this plugin function contain a [`NativeCallContext`] parameter?
+    #[must_use]
+    fn has_context(&self) -> bool;
+
     /// Is this plugin function pure?
     ///
     /// This defaults to `true` such that any old implementation that has constant-checking code