diff --git a/ets2panda/checker/ets/function.cpp b/ets2panda/checker/ets/function.cpp
index 3bd487e0e0c49e4cbb19fb618c436ae6f6c307dd..de7b02378d9803479484e8d37ef553836b3bf63c 100644
--- a/ets2panda/checker/ets/function.cpp
+++ b/ets2panda/checker/ets/function.cpp
@@ -27,6 +27,7 @@
 #include "checker/types/ets/etsObjectType.h"
 #include "checker/types/ets/etsPartialTypeParameter.h"
 #include "checker/types/gradualType.h"
+#include "checker/types/typeError.h"
 #include "compiler/lowering/scopesInit/scopesInitPhase.h"
 #include "ir/base/catchClause.h"
 #include "ir/base/classDefinition.h"
@@ -528,6 +529,7 @@ bool ETSChecker::ValidateSignatureRequiredParams(Signature *substitutedSig,
             // Note: If the signatures are from lambdas, then they have no `Function`.
             ir::ScriptFunction *const lambda = argument->AsArrowFunctionExpression()->Function();
             auto targetParm = substitutedSig->GetSignatureInfo()->params[index]->Declaration()->Node();
+            ERROR_SANITY_CHECK(this, targetParm->IsETSParameterExpression(), return false);
             if (CheckLambdaAssignable(targetParm->AsETSParameterExpression(), lambda)) {
                 continue;
             }
diff --git a/ets2panda/checker/ets/helpers.cpp b/ets2panda/checker/ets/helpers.cpp
index 535a1adc4054046cf7763dad920e3ad694939845..be4b57afdab82ce7914cf4dc4a923446b932f901 100644
--- a/ets2panda/checker/ets/helpers.cpp
+++ b/ets2panda/checker/ets/helpers.cpp
@@ -1854,7 +1854,8 @@ Type *ETSChecker::ResolveReferencedType(varbinder::LocalVariable *refVar, const
         case ir::AstNodeType::CLASS_DECLARATION:
         case ir::AstNodeType::STRUCT_DECLARATION:
         case ir::AstNodeType::CLASS_DEFINITION:
-            if (refVar->Declaration()->Node()->AsClassDefinition()->IsNamespaceTransformed()) {
+            if (refVar->Declaration()->Node()->IsClassDefinition() &&
+                refVar->Declaration()->Node()->AsClassDefinition()->IsNamespaceTransformed()) {
                 LogError(diagnostic::NAMESPACE_AS_TYPE, {refVar->Name()}, name->Start());
                 return GlobalTypeError();
             }
diff --git a/ets2panda/test/ast/compiler/ets/resolve_class_declaration.ets b/ets2panda/test/ast/compiler/ets/resolve_class_declaration.ets
new file mode 100644
index 0000000000000000000000000000000000000000..97180f8bebc508b8226952cec153081ad05e92cc
--- /dev/null
+++ b/ets2panda/test/ast/compiler/ets/resolve_class_declaration.ets
@@ -0,0 +1,28 @@
+/*
+ * 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.
+ */
+
+interface I {
+    b5 : number;r_2.ETSGLOBAL::hot_catc {
+    return;
+}
+
+/* @@? 17:20 Error SyntaxError: Interface fields must have type annotation. */
+/* @@? 17:30 Error SyntaxError: Unexpected token, expected ','. */
+/* @@? 17:30 Error SyntaxError: Unexpected token, expected 'private' or identifier. */
+/* @@? 17:31 Error SyntaxError: Identifier expected. */
+/* @@? 17:31 Error SyntaxError: Unexpected token, expected ','. */
+/* @@? 17:31 Error SyntaxError: Unexpected token, expected 'private' or identifier. */
+/* @@? 17:41 Error SyntaxError: Interface fields must have type annotation. */
+/* @@? 18:5 Error SyntaxError: Invalid Type. */
diff --git a/ets2panda/test/ast/compiler/ets/signature_param.ets b/ets2panda/test/ast/compiler/ets/signature_param.ets
new file mode 100644
index 0000000000000000000000000000000000000000..9c758d79536dcf8a7666d2b41a8b87d601229938
--- /dev/null
+++ b/ets2panda/test/ast/compiler/ets/signature_param.ets
@@ -0,0 +1,48 @@
+/*
+ * 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.
+ */
+
+function foo1(f: () => void) {
+    try {
+
+    } catch (e) {
+        arktest.assertTrue(false, "expected}
+}
+
+class A {}
+
+function foo2(let f = ((x:A {}
+
+function foo3() {
+    foo2(() => {}});
+    foo2(() => {});
+}
+
+/* @@? 20:35 Error SyntaxError: Newline is not allowed in strings */
+/* @@? 20:45 Error SyntaxError: Unexpected token, expected ',' or ')'. */
+/* @@? 22:1 Error SyntaxError: Illegal start of CLASS expression. */
+/* @@? 24:1 Error SyntaxError: Unexpected token, expected ')'. */
+/* @@? 24:1 Error SyntaxError: Unexpected token '{'. */
+/* @@? 24:1 Error SyntaxError: Unexpected token, expected ')'. */
+/* @@? 24:1 Error SyntaxError: Expected '{', got 'let'. */
+/* @@? 24:1 Error SyntaxError: Unexpected token, expected ',' or ')'. */
+/* @@? 24:1 Error SyntaxError: Parameter declaration should have an explicit type annotation. */
+/* @@? 24:1 Error SyntaxError: Unexpected token, expected an identifier. */
+/* @@? 24:1 Error SyntaxError: Nested functions are not allowed. */
+/* @@? 24:1 Error TypeError: Variable 'f' has already been declared. */
+/* @@? 24:1 Error TypeError: Unresolved reference x */
+/* @@? 26:1 Error SyntaxError: Nested functions are not allowed. */
+/* @@? 27:18 Error SyntaxError: Unexpected token, expected ',' or ')'. */
+/* @@? 27:18 Error SyntaxError: Unexpected token ')'. */
+/* @@? 28:21 Error TypeError: Unresolved reference foo2 */