diff --git a/tests/dlopen_test.cpp b/tests/dlopen_test.cpp
index 5b5c7f6..d38d8c5 100644
--- a/tests/dlopen_test.cpp
+++ b/tests/dlopen_test.cpp
@@ -58,7 +58,7 @@
 #endif
 }
 
-static void* ConcurrentDlErrorFn(void* arg) {
+static void* ConcurrentDlErrorFn(void*) {
   dlopen("/child/thread", RTLD_NOW);
   return reinterpret_cast<void*>(strdup(dlerror()));
 }