diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 4a5a85db1398b..20f70b867980e 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -25081,7 +25081,7 @@ namespace ts {
             const substituteConstraints = !(checkMode && checkMode & CheckMode.Inferential) &&
                 someType(type, isGenericTypeWithUnionConstraint) &&
                 (isConstraintPosition(type, reference) || hasContextualTypeWithNoGenericTypes(reference, checkMode));
-            return substituteConstraints ? mapType(type, t => t.flags & TypeFlags.Instantiable && !isMappedTypeGenericIndexedAccess(t) ? getBaseConstraintOrType(t) : t) : type;
+            return substituteConstraints ? mapType(type, t => t.flags & TypeFlags.Instantiable ? getBaseConstraintOrType(t) : t) : type;
         }
 
         function isExportOrExportExpression(location: Node) {