diff --git a/src/parseTools.mjs b/src/parseTools.mjs
index 0a9fb43b14b2..01dfafceb571 100644
--- a/src/parseTools.mjs
+++ b/src/parseTools.mjs
@@ -964,8 +964,7 @@ function from64Expr(x, assign = true) {
 }
 
 function toIndexType(x) {
-  if (MEMORY64 != 1) return x;
-  return `toIndexType(${x})`;
+  return to64(x);
 }
 
 function to64(x) {
diff --git a/src/runtime_shared.js b/src/runtime_shared.js
index 5606ac4c9116..9a9943c3ad13 100644
--- a/src/runtime_shared.js
+++ b/src/runtime_shared.js
@@ -47,22 +47,6 @@ function updateMemoryViews() {
 #endif
 }
 
-#if MEMORY64 == 1
-var toIndexType = (function() {
-  // Probe for support of bigint bounds with memory64.
-  // TODO(sbc): Remove this once all browsers start requiring bigint here.
-  // See https://github.com/WebAssembly/memory64/issues/68
-  var bigintMemoryBounds = 1;
-  try {
-    /** @suppress {checkTypes} */
-    new WebAssembly.Memory({'initial': 1n, 'index': 'i64'});
-  } catch (e) {
-    bigintMemoryBounds = 0;
-  }
-  return (i) => bigintMemoryBounds ? BigInt(i) : i;
-})();
-#endif
-
 #if ENVIRONMENT_MAY_BE_NODE && MIN_NODE_VERSION < 160000
 // The performance global was added to node in v16.0.0:
 // https://nodejs.org/api/globals.html#performance
diff --git a/test/other/codesize/test_codesize_minimal_64.gzsize b/test/other/codesize/test_codesize_minimal_64.gzsize
index 4f6685469880..522e1e95a572 100644
--- a/test/other/codesize/test_codesize_minimal_64.gzsize
+++ b/test/other/codesize/test_codesize_minimal_64.gzsize
@@ -1 +1 @@
-1579
+1517
diff --git a/test/other/codesize/test_codesize_minimal_64.jssize b/test/other/codesize/test_codesize_minimal_64.jssize
index 61e917f5ac04..ea894eaf5f04 100644
--- a/test/other/codesize/test_codesize_minimal_64.jssize
+++ b/test/other/codesize/test_codesize_minimal_64.jssize
@@ -1 +1 @@
-3257
+3139