2 files changed, 11 insertions, 2 deletions
diff --git a/src/tools/fuzzing.h b/src/tools/fuzzing.h
index 595652c94..8bfb119da 100644
--- a/src/tools/fuzzing.h
+++ b/src/tools/fuzzing.h
@@ -673,8 +673,9 @@ private:
     Index numVars = upToSquared(MAX_VARS);
     for (Index i = 0; i < numVars; i++) {
       auto type = getConcreteType();
-      if (type.isRef() && !type.isNullable()) {
-        // We can't use a nullable type as a var, which is null-initialized.
+      if (!type.isDefaultable()) {
+        // We can't use a nondefaultable type as a var, as those must be
+        // initialized to some default value.
         continue;
       }
       funcContext->typeLocals[type].push_back(params.size() +
diff --git a/src/wasm/wasm-type.cpp b/src/wasm/wasm-type.cpp
index 73ff47ee8..2c516ed98 100644
--- a/src/wasm/wasm-type.cpp
+++ b/src/wasm/wasm-type.cpp
@@ -587,6 +587,14 @@ bool Type::isDefaultable() const {
   // A variable can get a default value if its type is concrete (unreachable
   // and none have no values, hence no default), and if it's a reference, it
   // must be nullable.
+  if (isTuple()) {
+    for (auto t : *this) {
+      if (!t.isDefaultable()) {
+        return false;
+      }
+    }
+    return true;
+  }
   return isConcrete() && (!isRef() || isNullable()) && !isRtt();
 }