diff --git a/ets2panda/checker/ETSAnalyzerHelpers.cpp b/ets2panda/checker/ETSAnalyzerHelpers.cpp
index 644bdb35c6861e667ed1bb1c5736a11d153ffa8b..d6d7255b0aba4a661c40c27a1c4b1c2e65192268 100644
--- a/ets2panda/checker/ETSAnalyzerHelpers.cpp
+++ b/ets2panda/checker/ETSAnalyzerHelpers.cpp
@@ -213,7 +213,7 @@ void DoBodyTypeChecking(ETSChecker *checker, ir::MethodDefinition *node, ir::Scr
         checker->AddStatus(checker::CheckerStatus::IN_CONSTRUCTOR);
     }
 
-    if (node->IsExtensionMethod()) {
+    if (node->IsExtensionMethod() && scriptFunc->Signature() != nullptr) {
         CheckExtensionMethod(checker, scriptFunc, node);
     }
 
diff --git a/ets2panda/test/ast/parser/ets/extension_function_tests/extension_function_error1.ets b/ets2panda/test/ast/parser/ets/extension_function_tests/extension_function_error1.ets
new file mode 100644
index 0000000000000000000000000000000000000000..47d3887c4c2635fdf1c73651156c33eea74ed591
--- /dev/null
+++ b/ets2panda/test/ast/parser/ets/extension_function_tests/extension_function_error1.ets
@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2025 Huawei Device Co., Ltd.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+@AnimatableExtend
+function animatableWidth(this: TextAttribute, this { this.width(width); return this;
+}
+
+/* @@? 16:2 Error TypeError: Cannot find type 'AnimatableExtend'. */
+/* @@? 17:32 Error TypeError: Cannot find type 'TextAttribute'. */
+/* @@? 17:52 Error SyntaxError: The function parameter 'this' must explicitly specify the typeAnnotation. */
+/* @@? 17:52 Error SyntaxError: Unexpected token, expected ',' or ')'. */
+/* @@? 17:54 Error TypeError: Cannot reference 'this' in this context. */
+/* @@? 17:59 Error TypeError: Property 'width' does not exist on type 'Error' */
diff --git a/ets2panda/test/ast/parser/ets/extension_function_tests/extension_function_error2.ets b/ets2panda/test/ast/parser/ets/extension_function_tests/extension_function_error2.ets
new file mode 100644
index 0000000000000000000000000000000000000000..752a06d4cceb6598bb28c56cf9d6fa2f6c135ed4
--- /dev/null
+++ b/ets2panda/test/ast/parser/ets/extension_function_tests/extension_function_error2.ets
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2025 Huawei Device Co., Ltd.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+let a = (this: TextAttribute, this { this.width(width); return this;
+}
+
+/* @@? 16:9 Error TypeError: 'this' cannot be referenced from a static context */
+/* @@? 16:9 Error TypeError: Cannot reference 'this' in this context. */
+/* @@? 16:9 Error TypeError: Type 'Error' cannot be assigned to type 'ETSGLOBAL' */
+/* @@? 16:14 Error SyntaxError: Unexpected token, expected ')'. */
+/* @@? 16:16 Error SyntaxError: Unexpected token 'TextAttribute'. */
+/* @@? 16:16 Error TypeError: Unresolved reference TextAttribute */
+/* @@? 16:29 Error SyntaxError: Unexpected token ','. */
+/* @@? 16:31 Error SyntaxError: Unexpected token 'this'. */
+/* @@? 16:31 Error TypeError: Cannot reference 'this' in this context. */
+/* @@? 16:36 Error SyntaxError: Unexpected token '{'. */
+/* @@? 16:38 Error TypeError: Cannot reference 'this' in this context. */
+/* @@? 16:43 Error TypeError: Property 'width' does not exist on type 'Error' */
+/* @@? 16:57 Error SyntaxError: return keyword should be used in function body. */
+/* @@? 16:64 Error TypeError: Cannot reference 'this' in this context. */
+/* @@? 16:64 Error TypeError: All return statements in the function should be empty or have a value. */