diff --git a/src/if_python3.c b/src/if_python3.c
index 9d53caf..a04cca3 100644
--- a/src/if_python3.c
+++ b/src/if_python3.c
@@ -2070,7 +2070,7 @@
 }
 
     int
-python3_version()
+python3_version(void)
 {
 #ifdef USE_LIMITED_API
     return Py_LIMITED_API;