diff --git a/src/scope.ts b/src/scope.ts
index 059f7178..bee086f5 100644
--- a/src/scope.ts
+++ b/src/scope.ts
@@ -535,23 +535,6 @@ export class Scope {
         }
     }
 
-    // shadow copy
-    copy(scope: Scope) {
-        scope.kind = this.kind;
-        scope.name = this.name;
-        scope.children = this.children;
-        scope.parent = this.parent;
-        scope.namedTypeMap = this.namedTypeMap;
-        scope.debugFilePath = this.debugFilePath;
-        scope.tempVarArray = this.tempVarArray;
-        scope.variableArray = this.variableArray;
-        scope.statementArray = this.statementArray;
-        scope.localIndex = this.localIndex;
-        scope.mangledName = this.mangledName;
-        scope.modifiers = this.modifiers;
-        if (this.genericOwner) scope.setGenericOwner(this.genericOwner);
-    }
-
     // process generic specialization
     specialize(scope: Scope) {
         scope.kind = this.kind;
@@ -587,13 +570,6 @@ export class ClosureEnvironment extends Scope {
         }
     }
 
-    copy(scope: ClosureEnvironment) {
-        super.copy(scope);
-        scope.kind = this.kind;
-        scope.hasFreeVar = this.hasFreeVar;
-        scope.contextVariable = this.contextVariable;
-    }
-
     specialize(scope: ClosureEnvironment) {
         super.specialize(scope);
         scope.kind = this.kind;
@@ -752,17 +728,6 @@ export class FunctionScope extends ClosureEnvironment {
         return this._className !== '';
     }
 
-    copy(funcScope: FunctionScope) {
-        super.copy(funcScope);
-        funcScope.kind = this.kind;
-        funcScope.parameterArray = this.parameterArray;
-        funcScope.functionType = this.functionType;
-        funcScope._className = this._className;
-        funcScope.realParamCtxType = this.realParamCtxType;
-        funcScope.oriFuncName = this.oriFuncName;
-        funcScope.debugLocations = this.debugLocations;
-    }
-
     specialize(funcScope: FunctionScope) {
         super.specialize(funcScope);
         funcScope.kind = this.kind;
@@ -815,13 +780,6 @@ export class ClassScope extends Scope {
         return this._classType;
     }
 
-    copy(classScope: ClassScope) {
-        super.copy(classScope);
-        classScope.kind = this.kind;
-        classScope.name = this.name;
-        classScope._classType = this._classType;
-    }
-
     specialize(classScope: ClassScope) {
         super.specialize(classScope);
         classScope.kind = this.kind;
diff --git a/src/variable.ts b/src/variable.ts
index 9b2147b8..52edd0b6 100644
--- a/src/variable.ts
+++ b/src/variable.ts
@@ -254,16 +254,6 @@ export class VariableScanner {
                 if (variableType instanceof TSEnum) {
                     variableType = variableType.memberType;
                 }
-                /* Sometimes the variable's type is inferred as a TSFunction with
-                    isDeclare == true, we need to treat it as non declare function
-                    here to keep the same calling convention for closure */
-                if (
-                    variableType instanceof TSFunction &&
-                    variableType.isDeclare
-                ) {
-                    variableType = variableType.clone();
-                    (variableType as TSFunction).isDeclare = false;
-                }
 
                 const variable = new Variable(
                     variableName,