diff --git a/src/compiler/translator/ParseContext.cpp b/src/compiler/translator/ParseContext.cpp
index ee6b55f2e8..c0afdcbf51 100644
--- a/src/compiler/translator/ParseContext.cpp
+++ b/src/compiler/translator/ParseContext.cpp
@@ -6440,6 +6440,15 @@ TIntermTyped *TParseContext::addConstructor(TFunctionLookup *fnCall, const TSour
         ASSERT(!type.isUnsizedArray());
     }
 
+    // Security: enforce the same size limits on anonymous constructor temporaries
+    // as on declared variables. Without this, a WebGL shader can construct
+    // multi-gigabyte temporaries inline and pass them to the native driver,
+    // bypassing kWebGLMaxPrivateVariableSizeInBytes / kWebGLMaxVariableSizeInBytes.
+    if (type.getBasicType() == EbtStruct || type.isArray())
+    {
+        checkVariableSize(line, ImmutableString("constructor"), &type);
+    }
+
     if (!checkConstructorArguments(line, arguments, type))
     {
         return CreateZeroNode(type);