diff --git a/unittests/ExecutionEngine/JIT/JITTest.cpp b/unittests/ExecutionEngine/JIT/JITTest.cpp
index 5e2af030f20..44ea2130166 100644
--- a/unittests/ExecutionEngine/JIT/JITTest.cpp
+++ b/unittests/ExecutionEngine/JIT/JITTest.cpp
@@ -633,6 +633,7 @@ TEST_F(JITTest, AvailableExternallyGlobalIsntEmitted) {
 // This function is intentionally defined differently in the statically-compiled
 // program from the IR input to the JIT to assert that the JIT doesn't use its
 // definition.
+extern "C" int32_t JITTest_AvailableExternallyFunction() __attribute__((used));
 extern "C" int32_t JITTest_AvailableExternallyFunction() {
   return 42;
 }