diff --git a/src/compiler/transformers/es2017.ts b/src/compiler/transformers/es2017.ts
index ade1d41b010..66f10db0991 100644
--- a/src/compiler/transformers/es2017.ts
+++ b/src/compiler/transformers/es2017.ts
@@ -46,7 +46,7 @@ namespace ts {
         /** Whether the async function contains an element access on super (`super[x]`). */
         let hasSuperElementAccess: boolean;
         /** A set of node IDs for generated super accessors (variable statements). */
-        const substitutedSuperAccessors: boolean[] = [];
+        const substitutedSuperAccessors = new Set<Node>();
 
         let contextFlags: ContextFlags = 0;
 
@@ -503,7 +503,7 @@ namespace ts {
                     enableSubstitutionForAsyncMethodsWithSuper();
                     if (capturedSuperProperties.size) {
                         const variableStatement = createSuperAccessVariableStatement(factory, resolver, node, capturedSuperProperties);
-                        substitutedSuperAccessors[getNodeId(variableStatement)] = true;
+                        substitutedSuperAccessors.add(variableStatement);
                         insertStatementsAfterStandardPrologue(statements, [variableStatement]);
                     }
                 }
@@ -613,7 +613,7 @@ namespace ts {
                 }
             }
             // Disable substitution in the generated super accessor itself.
-            else if (enabledSubstitutions && substitutedSuperAccessors[getNodeId(node)]) {
+            else if (enabledSubstitutions && substitutedSuperAccessors.has(node)) {
                 const savedEnclosingSuperContainerFlags = enclosingSuperContainerFlags;
                 enclosingSuperContainerFlags = 0;
                 previousOnEmitNode(hint, node, emitCallback);
diff --git a/src/compiler/transformers/es2018.ts b/src/compiler/transformers/es2018.ts
index 846fd992ff2..f18c0964f61 100644
--- a/src/compiler/transformers/es2018.ts
+++ b/src/compiler/transformers/es2018.ts
@@ -70,7 +70,7 @@ namespace ts {
         /** Whether the async function contains an element access on super (`super[x]`). */
         let hasSuperElementAccess: boolean;
         /** A set of node IDs for generated super accessors. */
-        const substitutedSuperAccessors: boolean[] = [];
+        const substitutedSuperAccessors = new Set<Node>();
 
         return chainBundle(context, transformSourceFile);
 
@@ -972,7 +972,7 @@ namespace ts {
             if (emitSuperHelpers) {
                 enableSubstitutionForAsyncMethodsWithSuper();
                 const variableStatement = createSuperAccessVariableStatement(factory, resolver, node, capturedSuperProperties);
-                substitutedSuperAccessors[getNodeId(variableStatement)] = true;
+                substitutedSuperAccessors.add(variableStatement);
                 insertStatementsAfterStandardPrologue(statements, [variableStatement]);
             }
 
@@ -1087,7 +1087,7 @@ namespace ts {
                 }
             }
             // Disable substitution in the generated super accessor itself.
-            else if (enabledSubstitutions && substitutedSuperAccessors[getNodeId(node)]) {
+            else if (enabledSubstitutions && substitutedSuperAccessors.has(node)) {
                 const savedEnclosingSuperContainerFlags = enclosingSuperContainerFlags;
                 enclosingSuperContainerFlags = 0 as NodeCheckFlags;
                 previousOnEmitNode(hint, node, emitCallback);