diff --git a/src/ir/metadata.cpp b/src/ir/metadata.cpp
index f69927ecc10..a717766e627 100644
--- a/src/ir/metadata.cpp
+++ b/src/ir/metadata.cpp
@@ -76,9 +76,6 @@ void copyBetweenFunctions(Expression* origin,
   }
 }
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
-
 // Given two expressions to use as keys, see if they have identical values (or
 // are both absent) in two maps.
 template<typename T, typename V>
@@ -138,6 +135,4 @@ bool equal(Function* a, Function* b) {
   return true;
 }
 
-#pragma GCC diagnostic pop
-
 } // namespace wasm::metadata
diff --git a/src/parser/wast-parser.cpp b/src/parser/wast-parser.cpp
index 721b6126948..acc584fff38 100644
--- a/src/parser/wast-parser.cpp
+++ b/src/parser/wast-parser.cpp
@@ -520,9 +520,6 @@ Result<WASTCommand> command(Lexer& in) {
   return *module;
 }
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
-
 Result<WASTScript> wast(Lexer& in) {
   WASTScript cmds;
   while (!in.empty()) {
@@ -548,8 +545,6 @@ Result<WASTScript> wast(Lexer& in) {
   return cmds;
 }
 
-#pragma GCC diagnostic pop
-
 } // anonymous namespace
 
 Result<WASTScript> parseScript(std::string_view in) {
diff --git a/src/parser/wat-parser.h b/src/parser/wat-parser.h
index ba1236ad9a5..d0bb3f481a2 100644
--- a/src/parser/wat-parser.h
+++ b/src/parser/wat-parser.h
@@ -41,17 +41,12 @@ Result<> parseModuleBody(Module& wasm, Lexer& lexer);
 
 Result<Literal> parseConst(Lexer& lexer);
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
-
 struct InvokeAction {
   std::optional<Name> base;
   Name name;
   Literals args;
 };
 
-#pragma GCC diagnostic pop
-
 struct GetAction {
   std::optional<Name> base;
   Name name;
diff --git a/src/passes/Strip.cpp b/src/passes/Strip.cpp
index 51a12188352..19bc099de08 100644
--- a/src/passes/Strip.cpp
+++ b/src/passes/Strip.cpp
@@ -27,9 +27,6 @@
 
 namespace wasm {
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
-
 struct Strip : public Pass {
   bool requiresNonNullableLocalFixups() override { return false; }
 
@@ -77,6 +74,4 @@ Pass* createStripProducersPass() {
   });
 }
 
-#pragma GCC diagnostic pop
-
 } // namespace wasm
diff --git a/src/support/istring.h b/src/support/istring.h
index dad20b8fb00..162a9601986 100644
--- a/src/support/istring.h
+++ b/src/support/istring.h
@@ -36,9 +36,11 @@ struct IString {
   static std::string_view interned(std::string_view s, bool reuse = true);
 
 public:
-  const std::string_view str;
+  std::string_view str;
 
   IString() = default;
+  IString(const IString& other) = default;
+  IString& operator=(const IString& other) = default;
 
   // TODO: This is a wildly unsafe default inherited from the previous
   // implementation. Change it?
@@ -49,12 +51,6 @@ struct IString {
   IString(const char* str) : str(interned(str, false)) {}
   IString(const std::string& str) : str(interned(str, false)) {}
 
-  IString(const IString& other) = default;
-
-  IString& operator=(const IString& other) {
-    return *(new (this) IString(other));
-  }
-
   bool operator==(const IString& other) const {
     // Fast! No need to compare contents due to interning
     return str.data() == other.str.data();
diff --git a/src/support/string.cpp b/src/support/string.cpp
index bdb54f11f94..18f5cb51f7e 100644
--- a/src/support/string.cpp
+++ b/src/support/string.cpp
@@ -365,9 +365,6 @@ std::ostream& writeWTF16CodePoint(std::ostream& os, uint32_t u) {
   return os;
 }
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
-
 bool convertWTF8ToWTF16(std::ostream& os, std::string_view str) {
   bool valid = true;
   bool lastWasLeadingSurrogate = false;
@@ -393,8 +390,6 @@ bool convertWTF8ToWTF16(std::ostream& os, std::string_view str) {
   return valid;
 }
 
-#pragma GCC diagnostic pop
-
 bool convertWTF16ToWTF8(std::ostream& os, std::string_view str) {
   return doConvertWTF16ToWTF8(os, str, true);
 }
diff --git a/src/wasm-interpreter.h b/src/wasm-interpreter.h
index 4f979817226..960e86ffc82 100644
--- a/src/wasm-interpreter.h
+++ b/src/wasm-interpreter.h
@@ -4457,10 +4457,7 @@ class ModuleRunnerBase : public ExpressionRunner<SubType> {
     const auto& seg = *wasm.getDataSegment(curr->segment);
     auto elemBytes = element.getByteSize();
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
-
-    uint64_t end;
+    uint64_t end = 0;
     if (std::ckd_add(&end, offset, size * elemBytes) || end > seg.data.size()) {
       trap("out of bounds segment access in array.new_data");
     }
@@ -4473,8 +4470,6 @@ class ModuleRunnerBase : public ExpressionRunner<SubType> {
       contents.push_back(this->makeFromMemory(addr, element));
     }
 
-#pragma GCC diagnostic pop
-
     return self()->makeGCData(std::move(contents), curr->type);
   }
   Flow visitArrayNewElem(ArrayNewElem* curr) {
diff --git a/src/wasm-type.h b/src/wasm-type.h
index 0636181d299..b8d3632cb71 100644
--- a/src/wasm-type.h
+++ b/src/wasm-type.h
@@ -100,7 +100,7 @@ class HeapType {
   // stack, `HeapType` is used to describe the structures that reference types
   // refer to. HeapTypes are canonicalized and interned exactly like Types and
   // should also be passed by value.
-  uintptr_t id;
+  uintptr_t id = 0;
 
   static constexpr int TypeBits = 2;
   static constexpr int UsedBits = TypeBits + 1;