diff --git a/src/include/unit_test.h b/src/include/unit_test.h
index f9fac8f80b..9b92ee96f6 100644
--- a/src/include/unit_test.h
+++ b/src/include/unit_test.h
@@ -39,6 +39,7 @@
 
 #define ut_declare_test_c(test_function, test_class)	\
 	extern "C" {										\
+		int test_function(int argc, char *argv[]);		\
 		int test_function(int argc, char *argv[])		\
 		{												\
 			test_class* test = new test_class();		\