diff --git a/Objects/frameobject.c b/Objects/frameobject.c
index 7a9d40d..5e54585 100644
--- a/Objects/frameobject.c
+++ b/Objects/frameobject.c
@@ -127,7 +127,8 @@
 	if (!f->f_trace)
 	{
 		PyErr_Format(PyExc_ValueError,
-			     "f_lineno can only be set by a trace function");
+			     "f_lineno can only be set by a"
+			     " line trace function");
 		return -1;
 	}