diff --git a/llvm/lib/Fuzzer/test/AbsNegAndConstant64Test.cpp b/llvm/lib/Fuzzer/test/AbsNegAndConstant64Test.cpp
new file mode 100644
index 0000000..0d199fc
--- /dev/null
+++ b/llvm/lib/Fuzzer/test/AbsNegAndConstant64Test.cpp
@@ -0,0 +1,23 @@
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+
+// abs(x) < 0 and y == Const puzzle, 64-bit variant.
+#include <cstring>
+#include <cstdint>
+#include <cstdlib>
+#include <cstddef>
+#include <cstdio>
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+  if (Size < 16) return 0;
+  long x;
+  unsigned long y;
+  memcpy(&x, Data, 8);
+  memcpy(&y, Data + 8, 8);
+  if (labs(x) < 0 && y == 0xbaddcafedeadbeefUL) {
+    printf("BINGO; Found the target, exiting; x = 0x%lx y 0x%lx\n", x, y);
+    exit(1);
+  }
+  return 0;
+}
+