diff --git a/src/node-transformers/obfuscating-transformers/ClassDeclarationTransformer.ts b/src/node-transformers/obfuscating-transformers/ClassDeclarationTransformer.ts
index e5fbcd55..af98e720 100644
--- a/src/node-transformers/obfuscating-transformers/ClassDeclarationTransformer.ts
+++ b/src/node-transformers/obfuscating-transformers/ClassDeclarationTransformer.ts
@@ -137,7 +137,7 @@ export class ClassDeclarationTransformer extends AbstractNodeTransformer {
         blockScopeNode: TNodeWithBlockScope
     ): void {
         const cachedReplaceableIdentifiersNamesMap: TReplaceableIdentifiersNames =
-            this.replaceableIdentifiers.get(blockScopeNode)!;
+            <TReplaceableIdentifiersNames>this.replaceableIdentifiers.get(blockScopeNode);
 
         const cachedReplaceableIdentifiers: ESTree.Identifier[] | undefined = cachedReplaceableIdentifiersNamesMap
             .get(classDeclarationNode.id.name);
diff --git a/src/node-transformers/obfuscating-transformers/FunctionDeclarationTransformer.ts b/src/node-transformers/obfuscating-transformers/FunctionDeclarationTransformer.ts
index c69edc0c..5e48ce69 100644
--- a/src/node-transformers/obfuscating-transformers/FunctionDeclarationTransformer.ts
+++ b/src/node-transformers/obfuscating-transformers/FunctionDeclarationTransformer.ts
@@ -137,7 +137,7 @@ export class FunctionDeclarationTransformer extends AbstractNodeTransformer {
         blockScopeNode: TNodeWithBlockScope
     ): void {
         const cachedReplaceableIdentifiersNamesMap: TReplaceableIdentifiersNames =
-            this.replaceableIdentifiers.get(blockScopeNode)!;
+            <TReplaceableIdentifiersNames>this.replaceableIdentifiers.get(blockScopeNode);
 
         const cachedReplaceableIdentifiers: ESTree.Identifier[] | undefined = cachedReplaceableIdentifiersNamesMap
             .get(functionDeclarationNode.id.name);
diff --git a/src/node-transformers/obfuscating-transformers/VariableDeclarationTransformer.ts b/src/node-transformers/obfuscating-transformers/VariableDeclarationTransformer.ts
index eaeff73a..89783681 100644
--- a/src/node-transformers/obfuscating-transformers/VariableDeclarationTransformer.ts
+++ b/src/node-transformers/obfuscating-transformers/VariableDeclarationTransformer.ts
@@ -146,7 +146,7 @@ export class VariableDeclarationTransformer extends AbstractNodeTransformer {
         scopeNode: ESTree.Node
     ): void {
         const cachedReplaceableIdentifiersNamesMap: TReplaceableIdentifiersNames =
-            this.replaceableIdentifiers.get(scopeNode)!;
+            <TReplaceableIdentifiersNames>this.replaceableIdentifiers.get(scopeNode);
 
         const identifierNames: string[] = [];