diff --git a/libs/remix-debug/src/solidity-decoder/types/RefType.ts b/libs/remix-debug/src/solidity-decoder/types/RefType.ts
index 881667f8de..b19f0d3267 100644
--- a/libs/remix-debug/src/solidity-decoder/types/RefType.ts
+++ b/libs/remix-debug/src/solidity-decoder/types/RefType.ts
@@ -16,6 +16,14 @@ export class RefType {
     this.basicType = 'RefType'
   }
 
+  decodeFromStorage(input1? : any, input2? : any) {
+    throw new Error('This method is abstract');
+  }
+
+  decodeFromMemoryInternal(input1? : any, input2? : any, input3?: any) {
+    throw new Error('This method is abstract');
+  }
+
   /**
     * decode the type from the stack
     *
diff --git a/libs/remix-debug/src/solidity-decoder/types/ValueType.ts b/libs/remix-debug/src/solidity-decoder/types/ValueType.ts
index a657a51125..6d04a11d8a 100644
--- a/libs/remix-debug/src/solidity-decoder/types/ValueType.ts
+++ b/libs/remix-debug/src/solidity-decoder/types/ValueType.ts
@@ -14,6 +14,10 @@ export class ValueType {
     this.basicType = 'ValueType'
   }
 
+  decodeValue(input? : any) {
+    throw new Error('This method is abstract');
+  }
+
   /**
     * decode the type with the @arg location from the storage
     *