diff --git a/mfbt/tests/TestUniquePtr.cpp b/mfbt/tests/TestUniquePtr.cpp
index be49230e6e3c..dec8dcd5b082 100644
--- a/mfbt/tests/TestUniquePtr.cpp
+++ b/mfbt/tests/TestUniquePtr.cpp
@@ -322,7 +322,7 @@ static size_t DeleteIntFunctionCallCount = 0;
 
 static void DeleteIntFunction(void* aPtr) {
   DeleteIntFunctionCallCount++;
-  delete static_cast<int*>(aPtr);
+  delete[] static_cast<int*>(aPtr);
 }
 
 static void SetMallocedInt(UniquePtr<int, FreeSignature>& aPtr, int aI) {