diff --git a/src/engine.rs b/src/engine.rs
index 07740bad..ae295998 100644
--- a/src/engine.rs
+++ b/src/engine.rs
@@ -1681,7 +1681,9 @@ impl Engine {
                     let pos = rhs.position();
 
                     if self
-                        .call_native_fn(mods, state, lib, OP_EQUALS, hash_fn, args, false, pos)?
+                        .call_native_fn(
+                            mods, state, lib, OP_EQUALS, hash_fn, args, false, false, pos,
+                        )?
                         .0
                         .as_bool()
                         .unwrap_or(false)
@@ -1961,7 +1963,7 @@ impl Engine {
             let hash_fn =
                 calc_native_fn_hash(empty(), op, args.iter().map(|a| a.type_id())).unwrap();
 
-            match self.call_native_fn(mods, state, lib, op, hash_fn, args, true, op_pos) {
+            match self.call_native_fn(mods, state, lib, op, hash_fn, args, true, true, op_pos) {
                 Ok(_) => (),
                 Err(err) if matches!(err.as_ref(), EvalAltResult::ErrorFunctionNotFound(f, _) if f.starts_with(op)) =>
                 {
@@ -1971,8 +1973,8 @@ impl Engine {
                         calc_native_fn_hash(empty(), op, args.iter().map(|a| a.type_id())).unwrap();
 
                     // Run function
-                    let (value, _) =
-                        self.call_native_fn(mods, state, lib, op, hash_fn, args, true, op_pos)?;
+                    let (value, _) = self
+                        .call_native_fn(mods, state, lib, op, hash_fn, args, true, false, op_pos)?;
 
                     *args[0] = value.flatten();
                 }
diff --git a/src/optimize.rs b/src/optimize.rs
index 64b6140d..64609e60 100644
--- a/src/optimize.rs
+++ b/src/optimize.rs
@@ -149,6 +149,7 @@ fn call_fn_with_constant_arguments(
             hash_fn.unwrap(),
             arg_values.iter_mut().collect::<StaticVec<_>>().as_mut(),
             false,
+            false,
             Position::NONE,
         )
         .ok()
diff --git a/src/packages/logic.rs b/src/packages/logic.rs
index 8876b5a6..fdd6e0a3 100644
--- a/src/packages/logic.rs
+++ b/src/packages/logic.rs
@@ -145,7 +145,12 @@ mod logic_functions {
         }
 
         Err(Box::new(EvalAltResult::ErrorFunctionNotFound(
-            format!("{} ({}, {})", ctx.fn_name(), x.type_name(), y.type_name()),
+            format!(
+                "{} ({}, {})",
+                ctx.fn_name(),
+                ctx.engine().map_type_name(x.type_name()),
+                ctx.engine().map_type_name(y.type_name())
+            ),
             Position::NONE,
         )))
     }
diff --git a/src/token.rs b/src/token.rs
index 7e2c7b42..ea25f37a 100644
--- a/src/token.rs
+++ b/src/token.rs
@@ -1657,14 +1657,6 @@ pub fn is_valid_identifier(name: impl Iterator<Item = char>) -> bool {
     first_alphabetic
 }
 
-/// Is a text string an assignment operator?
-pub fn is_assignment_operator(op: &str) -> bool {
-    match op {
-        "+=" | "-=" | "*=" | "/=" | "<<=" | ">>=" | "&=" | "|=" | "^=" | "%=" | "**=" => true,
-        _ => false,
-    }
-}
-
 /// Is a character valid to start an identifier?
 #[cfg(feature = "unicode-xid-ident")]
 #[inline(always)]