diff --git a/src/ir/effects.h b/src/ir/effects.h
index 1e05ab0fb7c..e8ab4c8ef69 100644
--- a/src/ir/effects.h
+++ b/src/ir/effects.h
@@ -32,7 +32,7 @@ namespace wasm {
 
 class EffectAnalyzer {
 public:
-  EffectAnalyzer(const PassOptions& passOptions, Module& module)
+  EffectAnalyzer(const PassOptions& passOptions, const Module& module)
     : ignoreImplicitTraps(passOptions.ignoreImplicitTraps),
       trapsNeverHappen(passOptions.trapsNeverHappen), branchesOut(false),
       calls(false), readsMemory(false), writesMemory(false),
@@ -46,7 +46,7 @@ class EffectAnalyzer {
       features(module.features) {}
 
   EffectAnalyzer(const PassOptions& passOptions,
-                 Module& module,
+                 const Module& module,
                  Expression* ast)
     : EffectAnalyzer(passOptions, module) {
     walk(ast);
@@ -136,7 +136,7 @@ class EffectAnalyzer {
   // more here.)
   bool hasReturnCallThrow : 1;
 
-  Module& module;
+  const Module& module;
   FeatureSet features;
 
   std::set<Index> localsRead;
diff --git a/src/ir/intrinsics.h b/src/ir/intrinsics.h
index a9b32f31f1b..2f6809c826b 100644
--- a/src/ir/intrinsics.h
+++ b/src/ir/intrinsics.h
@@ -33,10 +33,10 @@
 namespace wasm {
 
 class Intrinsics {
-  Module& module;
+  const Module& module;
 
 public:
-  Intrinsics(Module& module) : module(module) {}
+  Intrinsics(const Module& module) : module(module) {}
 
   // Check if an instruction is the Binaryen call.without.effects intrinsic.
   //
diff --git a/src/ir/js-utils.h b/src/ir/js-utils.h
index 7591b4fe7e0..105dea499cf 100644
--- a/src/ir/js-utils.h
+++ b/src/ir/js-utils.h
@@ -45,7 +45,7 @@ inline bool hasPossibleJSPrototypeField(HeapType type) {
 
 // Calls flowIn and flowOut on all types that may flow in from or out to JS.
 template<typename In, typename Out>
-void iterJSInterface(Module& wasm, In flowIn, Out flowOut) {
+void iterJSInterface(const Module& wasm, In flowIn, Out flowOut) {
   // @binaryen.js.called functions are called from JS. Their parameters flow
   // in from JS and their results flow back out.
   for (auto f : Intrinsics(wasm).getJSCalledFunctions()) {
diff --git a/src/passes/Unsubtyping.cpp b/src/passes/Unsubtyping.cpp
index 5f01610adeb..f3165b8147c 100644
--- a/src/passes/Unsubtyping.cpp
+++ b/src/passes/Unsubtyping.cpp
@@ -645,7 +645,7 @@ struct Unsubtyping : Pass, Noter<Unsubtyping> {
     }
   }
 
-  void analyzeJSInterface(Module& wasm) {
+  void analyzeJSInterface(const Module& wasm) {
     if (!wasm.features.hasCustomDescriptors()) {
       return;
     }
diff --git a/src/wasm.h b/src/wasm.h
index 941d759ce6b..c64978014f9 100644
--- a/src/wasm.h
+++ b/src/wasm.h
@@ -2699,30 +2699,30 @@ class Module {
 public:
   Module() = default;
 
-  Export* getExport(Name name);
-  Function* getFunction(Name name);
-  Table* getTable(Name name);
-  ElementSegment* getElementSegment(Name name);
-  Memory* getMemory(Name name);
-  DataSegment* getDataSegment(Name name);
-  Global* getGlobal(Name name);
-  Tag* getTag(Name name);
-
-  Export* getExportOrNull(Name name);
-  Table* getTableOrNull(Name name);
-  Memory* getMemoryOrNull(Name name);
-  ElementSegment* getElementSegmentOrNull(Name name);
-  DataSegment* getDataSegmentOrNull(Name name);
-  Function* getFunctionOrNull(Name name);
-  Global* getGlobalOrNull(Name name);
-  Tag* getTagOrNull(Name name);
+  Export* getExport(Name name) const;
+  Function* getFunction(Name name) const;
+  Table* getTable(Name name) const;
+  ElementSegment* getElementSegment(Name name) const;
+  Memory* getMemory(Name name) const;
+  DataSegment* getDataSegment(Name name) const;
+  Global* getGlobal(Name name) const;
+  Tag* getTag(Name name) const;
+
+  Export* getExportOrNull(Name name) const;
+  Table* getTableOrNull(Name name) const;
+  Memory* getMemoryOrNull(Name name) const;
+  ElementSegment* getElementSegmentOrNull(Name name) const;
+  DataSegment* getDataSegmentOrNull(Name name) const;
+  Function* getFunctionOrNull(Name name) const;
+  Global* getGlobalOrNull(Name name) const;
+  Tag* getTagOrNull(Name name) const;
 
   // get* methods that are generic over the kind, that is, items are identified
   // by their kind and their name. Otherwise, they are similar to the above
   // get* methods. These return items that can be imports.
   // TODO: Add methods for things that cannot be imports (segments).
-  Importable* getImport(ModuleItemKind kind, Name name);
-  Importable* getImportOrNull(ModuleItemKind kind, Name name);
+  Importable* getImport(ModuleItemKind kind, Name name) const;
+  Importable* getImportOrNull(ModuleItemKind kind, Name name) const;
 
   Export* addExport(Export* curr);
   Function* addFunction(Function* curr);
diff --git a/src/wasm/wasm.cpp b/src/wasm/wasm.cpp
index 536f33ae59f..9be9b7b5cfa 100644
--- a/src/wasm/wasm.cpp
+++ b/src/wasm/wasm.cpp
@@ -22,6 +22,21 @@
 
 namespace wasm {
 
+namespace {
+
+template<typename Value>
+const Value& getModuleElement(const std::unordered_map<Name, Value>& m,
+                              Name name,
+                              std::string_view funcName) {
+  auto iter = m.find(name);
+  if (iter == m.end()) {
+    Fatal() << "Module::" << funcName << ": " << name << " does not exist";
+  }
+  return iter->second;
+}
+
+} // namespace
+
 // shared constants
 
 Name RETURN_FLOW("*return:)*");
@@ -1705,45 +1720,35 @@ void Function::clearDebugInfo() {
   epilogLocation.reset();
 }
 
-template<typename Map>
-typename Map::mapped_type&
-getModuleElement(Map& m, Name name, std::string_view funcName) {
-  auto iter = m.find(name);
-  if (iter == m.end()) {
-    Fatal() << "Module::" << funcName << ": " << name << " does not exist";
-  }
-  return iter->second;
-}
-
-Export* Module::getExport(Name name) {
+Export* Module::getExport(Name name) const {
   return getModuleElement(exportsMap, name, "getExport");
 }
 
-Function* Module::getFunction(Name name) {
+Function* Module::getFunction(Name name) const {
   return getModuleElement(functionsMap, name, "getFunction");
 }
 
-Table* Module::getTable(Name name) {
+Table* Module::getTable(Name name) const {
   return getModuleElement(tablesMap, name, "getTable");
 }
 
-ElementSegment* Module::getElementSegment(Name name) {
+ElementSegment* Module::getElementSegment(Name name) const {
   return getModuleElement(elementSegmentsMap, name, "getElementSegment");
 }
 
-Memory* Module::getMemory(Name name) {
+Memory* Module::getMemory(Name name) const {
   return getModuleElement(memoriesMap, name, "getMemory");
 }
 
-DataSegment* Module::getDataSegment(Name name) {
+DataSegment* Module::getDataSegment(Name name) const {
   return getModuleElement(dataSegmentsMap, name, "getDataSegment");
 }
 
-Global* Module::getGlobal(Name name) {
+Global* Module::getGlobal(Name name) const {
   return getModuleElement(globalsMap, name, "getGlobal");
 }
 
-Tag* Module::getTag(Name name) {
+Tag* Module::getTag(Name name) const {
   return getModuleElement(tagsMap, name, "getTag");
 }
 
@@ -1756,39 +1761,39 @@ typename Map::mapped_type getModuleElementOrNull(Map& m, Name name) {
   return iter->second;
 }
 
-Export* Module::getExportOrNull(Name name) {
+Export* Module::getExportOrNull(Name name) const {
   return getModuleElementOrNull(exportsMap, name);
 }
 
-Function* Module::getFunctionOrNull(Name name) {
+Function* Module::getFunctionOrNull(Name name) const {
   return getModuleElementOrNull(functionsMap, name);
 }
 
-Table* Module::getTableOrNull(Name name) {
+Table* Module::getTableOrNull(Name name) const {
   return getModuleElementOrNull(tablesMap, name);
 }
 
-ElementSegment* Module::getElementSegmentOrNull(Name name) {
+ElementSegment* Module::getElementSegmentOrNull(Name name) const {
   return getModuleElementOrNull(elementSegmentsMap, name);
 }
 
-Memory* Module::getMemoryOrNull(Name name) {
+Memory* Module::getMemoryOrNull(Name name) const {
   return getModuleElementOrNull(memoriesMap, name);
 }
 
-DataSegment* Module::getDataSegmentOrNull(Name name) {
+DataSegment* Module::getDataSegmentOrNull(Name name) const {
   return getModuleElementOrNull(dataSegmentsMap, name);
 }
 
-Global* Module::getGlobalOrNull(Name name) {
+Global* Module::getGlobalOrNull(Name name) const {
   return getModuleElementOrNull(globalsMap, name);
 }
 
-Tag* Module::getTagOrNull(Name name) {
+Tag* Module::getTagOrNull(Name name) const {
   return getModuleElementOrNull(tagsMap, name);
 }
 
-Importable* Module::getImport(ModuleItemKind kind, Name name) {
+Importable* Module::getImport(ModuleItemKind kind, Name name) const {
   switch (kind) {
     case ModuleItemKind::Function:
       return getFunction(name);
@@ -1809,7 +1814,7 @@ Importable* Module::getImport(ModuleItemKind kind, Name name) {
   WASM_UNREACHABLE("unexpected kind");
 }
 
-Importable* Module::getImportOrNull(ModuleItemKind kind, Name name) {
+Importable* Module::getImportOrNull(ModuleItemKind kind, Name name) const {
   auto doReturn = [](Importable* importable) {
     return importable ? importable->imported() ? importable : nullptr : nullptr;
   };