diff --git a/src/packages/arithmetic.rs b/src/packages/arithmetic.rs
index ead54f8c..cf109b0c 100644
--- a/src/packages/arithmetic.rs
+++ b/src/packages/arithmetic.rs
@@ -275,27 +275,51 @@ def_package!(crate:ArithmeticPackage:"Basic arithmetic", lib, {
         #[cfg(not(feature = "unchecked"))]
         {
             // Checked basic arithmetic
-            reg_op!(lib, "+", add, i8, u8, i16, u16, i32, u32, u64, i128, u128);
-            reg_op!(lib, "-", sub, i8, u8, i16, u16, i32, u32, u64, i128, u128);
-            reg_op!(lib, "*", mul, i8, u8, i16, u16, i32, u32, u64, i128, u128);
-            reg_op!(lib, "/", div, i8, u8, i16, u16, i32, u32, u64, i128, u128);
+            reg_op!(lib, "+", add, i8, u8, i16, u16, i32, u32, u64);
+            reg_op!(lib, "-", sub, i8, u8, i16, u16, i32, u32, u64);
+            reg_op!(lib, "*", mul, i8, u8, i16, u16, i32, u32, u64);
+            reg_op!(lib, "/", div, i8, u8, i16, u16, i32, u32, u64);
             // Checked bit shifts
-            reg_op!(lib, "<<", shl, i8, u8, i16, u16, i32, u32, u64, i128, u128);
-            reg_op!(lib, ">>", shr, i8, u8, i16, u16, i32, u32, u64, i128, u128);
-            reg_op!(lib, "%", modulo, i8, u8, i16, u16, i32, u32, u64, i128, u128);
+            reg_op!(lib, "<<", shl, i8, u8, i16, u16, i32, u32, u64);
+            reg_op!(lib, ">>", shr, i8, u8, i16, u16, i32, u32, u64);
+            reg_op!(lib, "%", modulo, i8, u8, i16, u16, i32, u32, u64);
+
+            #[cfg(not(target_arch = "wasm32"))]
+            {
+                reg_op!(lib, "+", add, i128, u128);
+                reg_op!(lib, "-", sub, i128, u128);
+                reg_op!(lib, "*", mul, i128, u128);
+                reg_op!(lib, "/", div, i128, u128);
+                // Checked bit shifts
+                reg_op!(lib, "<<", shl, i128, u128);
+                reg_op!(lib, ">>", shr, i128, u128);
+                reg_op!(lib, "%", modulo, i128, u128);
+            }
         }
 
         #[cfg(feature = "unchecked")]
         {
             // Unchecked basic arithmetic
-            reg_op!(lib, "+", add_u, i8, u8, i16, u16, i32, u32, u64, i128, u128);
-            reg_op!(lib, "-", sub_u, i8, u8, i16, u16, i32, u32, u64, i128, u128);
-            reg_op!(lib, "*", mul_u, i8, u8, i16, u16, i32, u32, u64, i128, u128);
-            reg_op!(lib, "/", div_u, i8, u8, i16, u16, i32, u32, u64, i128, u128);
+            reg_op!(lib, "+", add_u, i8, u8, i16, u16, i32, u32, u64);
+            reg_op!(lib, "-", sub_u, i8, u8, i16, u16, i32, u32, u64);
+            reg_op!(lib, "*", mul_u, i8, u8, i16, u16, i32, u32, u64);
+            reg_op!(lib, "/", div_u, i8, u8, i16, u16, i32, u32, u64);
             // Unchecked bit shifts
-            reg_op!(lib, "<<", shl_u, i64, i8, u8, i16, u16, i32, u32, u64, i128, u128);
-            reg_op!(lib, ">>", shr_u, i64, i8, u8, i16, u16, i32, u32, u64, i128, u128);
-            reg_op!(lib, "%", modulo_u, i8, u8, i16, u16, i32, u32, u64, i128, u128);
+            reg_op!(lib, "<<", shl_u, i64, i8, u8, i16, u16, i32, u32, u64);
+            reg_op!(lib, ">>", shr_u, i64, i8, u8, i16, u16, i32, u32, u64);
+            reg_op!(lib, "%", modulo_u, i8, u8, i16, u16, i32, u32, u64);
+
+            #[cfg(not(target_arch = "wasm32"))]
+            {
+                reg_op!(lib, "+", add_u, i128, u128);
+                reg_op!(lib, "-", sub_u, i128, u128);
+                reg_op!(lib, "*", mul_u, i128, u128);
+                reg_op!(lib, "/", div_u, i128, u128);
+                // Unchecked bit shifts
+                reg_op!(lib, "<<", shl_u, i128, u128);
+                reg_op!(lib, ">>", shr_u, i128, u128);
+                reg_op!(lib, "%", modulo_u, i128, u128);
+            }
         }
     }
 
@@ -311,9 +335,16 @@ def_package!(crate:ArithmeticPackage:"Basic arithmetic", lib, {
     #[cfg(not(feature = "only_i32"))]
     #[cfg(not(feature = "only_i64"))]
     {
-        reg_op!(lib, "|", binary_or, i8, u8, i16, u16, i32, u32, u64, i128, u128);
-        reg_op!(lib, "&", binary_and, i8, u8, i16, u16, i32, u32, u64, i128, u128);
-        reg_op!(lib, "^", binary_xor, i8, u8, i16, u16, i32, u32, u64, i128, u128);
+        reg_op!(lib, "|", binary_or, i8, u8, i16, u16, i32, u32, u64);
+        reg_op!(lib, "&", binary_and, i8, u8, i16, u16, i32, u32, u64);
+        reg_op!(lib, "^", binary_xor, i8, u8, i16, u16, i32, u32, u64);
+
+        #[cfg(not(target_arch = "wasm32"))]
+        {
+            reg_op!(lib, "|", binary_or, i128, u128);
+            reg_op!(lib, "&", binary_and, i128, u128);
+            reg_op!(lib, "^", binary_xor, i128, u128);
+        }
     }
 
     #[cfg(not(feature = "no_float"))]
@@ -343,8 +374,14 @@ def_package!(crate:ArithmeticPackage:"Basic arithmetic", lib, {
         #[cfg(not(feature = "only_i32"))]
         #[cfg(not(feature = "only_i64"))]
         {
-            reg_unary!(lib, "-", neg, i8, i16, i32, i64, i128);
-            reg_unary!(lib, "abs", abs, i8, i16, i32, i64, i128);
+            reg_unary!(lib, "-", neg, i8, i16, i32, i64);
+            reg_unary!(lib, "abs", abs, i8, i16, i32, i64);
+
+            #[cfg(not(target_arch = "wasm32"))]
+            {
+                reg_unary!(lib, "-", neg, i128);
+                reg_unary!(lib, "abs", abs, i128);
+            }
         }
     }
 
@@ -357,8 +394,14 @@ def_package!(crate:ArithmeticPackage:"Basic arithmetic", lib, {
         #[cfg(not(feature = "only_i32"))]
         #[cfg(not(feature = "only_i64"))]
         {
-            reg_unary!(lib, "-", neg_u, i8, i16, i32, i64, i128);
-            reg_unary!(lib, "abs", abs_u, i8, i16, i32, i64, i128);
+            reg_unary!(lib, "-", neg_u, i8, i16, i32, i64);
+            reg_unary!(lib, "abs", abs_u, i8, i16, i32, i64);
+
+            #[cfg(not(target_arch = "wasm32"))]
+            {
+                reg_unary!(lib, "-", neg_u, i128);
+                reg_unary!(lib, "abs", abs_u, i128);
+            }
         }
     }
 });
diff --git a/src/packages/array_basic.rs b/src/packages/array_basic.rs
index c6904e90..59358063 100644
--- a/src/packages/array_basic.rs
+++ b/src/packages/array_basic.rs
@@ -98,9 +98,16 @@ def_package!(crate:BasicArrayPackage:"Basic array utilities.", lib, {
     #[cfg(not(feature = "only_i32"))]
     #[cfg(not(feature = "only_i64"))]
     {
-        reg_op!(lib, "push", push, i8, u8, i16, u16, i32, i64, u32, u64, i128, u128);
-        reg_pad!(lib, "pad", pad, i8, u8, i16, u16, i32, u32, i64, u64, i128, u128);
-        reg_tri!(lib, "insert", ins, i8, u8, i16, u16, i32, i64, u32, u64, i128, u128);
+        reg_op!(lib, "push", push, i8, u8, i16, u16, i32, i64, u32, u64);
+        reg_pad!(lib, "pad", pad, i8, u8, i16, u16, i32, u32, i64, u64);
+        reg_tri!(lib, "insert", ins, i8, u8, i16, u16, i32, i64, u32, u64);
+
+        #[cfg(not(target_arch = "wasm32"))]
+        {
+            reg_op!(lib, "push", push, i128, u128);
+            reg_pad!(lib, "pad", pad, i128, u128);
+            reg_tri!(lib, "insert", ins, i128, u128);
+        }
     }
 
     #[cfg(not(feature = "no_float"))]
diff --git a/src/packages/iter_basic.rs b/src/packages/iter_basic.rs
index ebf55992..cccf4b6c 100644
--- a/src/packages/iter_basic.rs
+++ b/src/packages/iter_basic.rs
@@ -85,7 +85,10 @@ def_package!(crate:BasicIteratorPackage:"Basic range iterators.", lib, {
             )
         }
 
-        reg_range!(lib, "range", i8, u8, i16, u16, i32, i64, u32, u64, i128, u128);
+        reg_range!(lib, "range", i8, u8, i16, u16, i32, i64, u32, u64);
+
+        #[cfg(not(target_arch = "wasm32"))]
+        reg_range!(lib, "range", i128, u128);
     }
 
     reg_step::<INT>(lib);
@@ -103,6 +106,9 @@ def_package!(crate:BasicIteratorPackage:"Basic range iterators.", lib, {
             )
         }
 
-        reg_step!(lib, "range", i8, u8, i16, u16, i32, i64, u32, u64, i128, u128);
+        reg_step!(lib, "range", i8, u8, i16, u16, i32, i64, u32, u64);
+
+        #[cfg(not(target_arch = "wasm32"))]
+        reg_step!(lib, "range", i128, u128);
     }
 });
diff --git a/src/packages/logic.rs b/src/packages/logic.rs
index 41ca035f..1cb4b437 100644
--- a/src/packages/logic.rs
+++ b/src/packages/logic.rs
@@ -36,12 +36,22 @@ def_package!(crate:LogicPackage:"Logical operators.", lib, {
     #[cfg(not(feature = "only_i32"))]
     #[cfg(not(feature = "only_i64"))]
     {
-        reg_op!(lib, "<", lt, i8, u8, i16, u16, i32, u32, u64, i128, u128);
-        reg_op!(lib, "<=", lte, i8, u8, i16, u16, i32, u32, u64, i128, u128);
-        reg_op!(lib, ">", gt, i8, u8, i16, u16, i32, u32, u64, i128, u128);
-        reg_op!(lib, ">=", gte, i8, u8, i16, u16, i32, u32, u64, i128, u128);
-        reg_op!(lib, "==", eq, i8, u8, i16, u16, i32, u32, u64, i128, u128);
-        reg_op!(lib, "!=", ne, i8, u8, i16, u16, i32, u32, u64, i128, u128);
+        reg_op!(lib, "<", lt, i8, u8, i16, u16, i32, u32, u64);
+        reg_op!(lib, "<=", lte, i8, u8, i16, u16, i32, u32, u64);
+        reg_op!(lib, ">", gt, i8, u8, i16, u16, i32, u32, u64);
+        reg_op!(lib, ">=", gte, i8, u8, i16, u16, i32, u32, u64);
+        reg_op!(lib, "==", eq, i8, u8, i16, u16, i32, u32, u64);
+        reg_op!(lib, "!=", ne, i8, u8, i16, u16, i32, u32, u64);
+
+        #[cfg(not(target_arch = "wasm32"))]
+        {
+            reg_op!(lib, "<", lt, i128, u128);
+            reg_op!(lib, "<=", lte, i128, u128);
+            reg_op!(lib, ">", gt, i128, u128);
+            reg_op!(lib, ">=", gte, i128, u128);
+            reg_op!(lib, "==", eq, i128, u128);
+            reg_op!(lib, "!=", ne, i128, u128);
+        }
     }
 
     #[cfg(not(feature = "no_float"))]
diff --git a/src/packages/math_basic.rs b/src/packages/math_basic.rs
index eea49727..e7ce43b7 100644
--- a/src/packages/math_basic.rs
+++ b/src/packages/math_basic.rs
@@ -70,8 +70,12 @@ def_package!(crate:BasicMathPackage:"Basic mathematic functions.", lib, {
             lib.set_fn_1("to_float", |x: u32| Ok(x as FLOAT));
             lib.set_fn_1("to_float", |x: i64| Ok(x as FLOAT));
             lib.set_fn_1("to_float", |x: u64| Ok(x as FLOAT));
-            lib.set_fn_1("to_float", |x: i128| Ok(x as FLOAT));
-            lib.set_fn_1("to_float", |x: u128| Ok(x as FLOAT));
+
+            #[cfg(not(target_arch = "wasm32"))]
+            {
+                lib.set_fn_1("to_float", |x: i128| Ok(x as FLOAT));
+                lib.set_fn_1("to_float", |x: u128| Ok(x as FLOAT));
+            }
         }
     }
 
diff --git a/src/packages/string_basic.rs b/src/packages/string_basic.rs
index 262a4f3a..338cf5ec 100644
--- a/src/packages/string_basic.rs
+++ b/src/packages/string_basic.rs
@@ -52,9 +52,16 @@ def_package!(crate:BasicStringPackage:"Basic string utilities, including printin
         reg_op!(lib, KEYWORD_PRINT, to_string, i8, u8, i16, u16, i32, u32);
         reg_op!(lib, FUNC_TO_STRING, to_string, i8, u8, i16, u16, i32, u32);
         reg_op!(lib, KEYWORD_DEBUG, to_debug, i8, u8, i16, u16, i32, u32);
-        reg_op!(lib, KEYWORD_PRINT, to_string, i64, u64, i128, u128);
-        reg_op!(lib, FUNC_TO_STRING, to_string, i64, u64, i128, u128);
-        reg_op!(lib, KEYWORD_DEBUG, to_debug, i64, u64, i128, u128);
+        reg_op!(lib, KEYWORD_PRINT, to_string, i64, u64);
+        reg_op!(lib, FUNC_TO_STRING, to_string, i64, u64);
+        reg_op!(lib, KEYWORD_DEBUG, to_debug, i64, u64);
+
+        #[cfg(not(target_arch = "wasm32"))]
+        {
+            reg_op!(lib, KEYWORD_PRINT, to_string, i128, u128);
+            reg_op!(lib, FUNC_TO_STRING, to_string, i128, u128);
+            reg_op!(lib, KEYWORD_DEBUG, to_debug, i128, u128);
+        }
     }
 
     #[cfg(not(feature = "no_float"))]
diff --git a/src/packages/string_more.rs b/src/packages/string_more.rs
index 8f8d1731..46805750 100644
--- a/src/packages/string_more.rs
+++ b/src/packages/string_more.rs
@@ -95,8 +95,14 @@ def_package!(crate:MoreStringPackage:"Additional string utilities, including str
     #[cfg(not(feature = "only_i32"))]
     #[cfg(not(feature = "only_i64"))]
     {
-        reg_op!(lib, "+", append, i8, u8, i16, u16, i32, i64, u32, u64, i128, u128);
-        reg_op!(lib, "+", prepend, i8, u8, i16, u16, i32, i64, u32, u64, i128, u128);
+        reg_op!(lib, "+", append, i8, u8, i16, u16, i32, i64, u32, u64);
+        reg_op!(lib, "+", prepend, i8, u8, i16, u16, i32, i64, u32, u64);
+
+        #[cfg(not(target_arch = "wasm32"))]
+        {
+            reg_op!(lib, "+", append, i128, u128);
+            reg_op!(lib, "+", prepend, i128, u128);
+        }
     }
 
     #[cfg(not(feature = "no_float"))]
diff --git a/src/stdlib.rs b/src/stdlib.rs
index 1d1397d5..64eda6fb 100644
--- a/src/stdlib.rs
+++ b/src/stdlib.rs
@@ -4,10 +4,13 @@
 mod inner {
     pub use core::{
         any, arch, array, ascii, cell, char, clone, cmp, convert, default, f32, f64, ffi, fmt,
-        future, hash, hint, i128, i16, i32, i64, i8, isize, iter, marker, mem, num, ops, option,
-        panic, pin, prelude, ptr, result, slice, str, task, time, u128, u16, u32, u64, u8, usize,
+        future, hash, hint, i16, i32, i64, i8, isize, iter, marker, mem, num, ops, option, panic,
+        pin, prelude, ptr, result, slice, str, task, time, u16, u32, u64, u8, usize,
     };
 
+    #[cfg(not(target_arch = "wasm32"))]
+    pub use core::{i128, u128};
+
     pub use alloc::{borrow, boxed, format, rc, string, sync, vec};
 
     pub use core_error as error;