diff --git a/llvm/lib/Transforms/IPO/Attributor.cpp b/llvm/lib/Transforms/IPO/Attributor.cpp
--- a/llvm/lib/Transforms/IPO/Attributor.cpp
+++ b/llvm/lib/Transforms/IPO/Attributor.cpp
@@ -4335,7 +4335,7 @@
 
     if (IsMalloc) {
       if (auto *Size = dyn_cast<ConstantInt>(I.getOperand(0)))
-        if (Size->getValue().sle(MaxHeapToStackSize))
+        if (Size->getValue().ule(MaxHeapToStackSize))
           if (UsesCheck(I) || FreeCheck(I)) {
             MallocCalls.insert(&I);
             return true;
@@ -4345,7 +4345,7 @@
       if (auto *Num = dyn_cast<ConstantInt>(I.getOperand(0)))
         if (auto *Size = dyn_cast<ConstantInt>(I.getOperand(1)))
           if ((Size->getValue().umul_ov(Num->getValue(), Overflow))
-                  .sle(MaxHeapToStackSize))
+                  .ule(MaxHeapToStackSize))
             if (!Overflow && (UsesCheck(I) || FreeCheck(I))) {
               MallocCalls.insert(&I);
               return true;
diff --git a/llvm/test/Transforms/Attributor/heap_to_stack.ll b/llvm/test/Transforms/Attributor/heap_to_stack.ll
--- a/llvm/test/Transforms/Attributor/heap_to_stack.ll
+++ b/llvm/test/Transforms/Attributor/heap_to_stack.ll
@@ -313,15 +313,27 @@
 
 define i32 @test_sle() {
   %1 = tail call noalias i8* @malloc(i64 -1)
-  ; FIXME: This should not be transformed
-  ; CHECK: %1 = alloca i8, i64 -1
-  ; CHECK-NEXT: @no_sync_func(i8* noalias nocapture nofree %1)
+  ; CHECK: %1 = tail call noalias i8* @malloc(i64 -1)
+  ; CHECK-NEXT: @no_sync_func(i8* noalias nofree %1)
   tail call void @no_sync_func(i8* %1)
   %2 = bitcast i8* %1 to i32*
   store i32 10, i32* %2
   %3 = load i32, i32* %2
   tail call void @free(i8* %1)
-  ; CHECK-NOT: tail call void @free(i8* noalias %1)
+  ; CHECK: tail call void @free(i8* noalias %1)
+  ret i32 %3
+}
+
+define i32 @test_overflow() {
+  %1 = tail call noalias i8* @calloc(i64 65537, i64 65537)
+  ; CHECK: %1 = tail call noalias i8* @calloc(i64 65537, i64 65537)
+  ; CHECK-NEXT: @no_sync_func(i8* noalias nofree %1)
+  tail call void @no_sync_func(i8* %1)
+  %2 = bitcast i8* %1 to i32*
+  store i32 10, i32* %2
+  %3 = load i32, i32* %2
+  tail call void @free(i8* %1)
+  ; CHECK: tail call void @free(i8* noalias %1)
   ret i32 %3
 }