diff --git a/Python/importdl.c b/Python/importdl.c
index 40b37d2..157257f 100644
--- a/Python/importdl.c
+++ b/Python/importdl.c
@@ -577,7 +577,7 @@
 #endif
 	if (p == NULL) {
 		PyErr_Format(PyExc_ImportError,
-		   "dynamic module does not define init function (%s)",
+		   "dynamic module does not define init function (%.200s)",
 			     funcname);
 		return NULL;
 	}