diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index 03b0705..e6decaa 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -55,7 +55,7 @@
 	else if (errno == ERANGE)
 		err_setstr(OverflowError, "math range error");
 	else
-		err_errno(RuntimeError);
+		err_errno(ValueError); /* Unexpected math error */
 	return NULL;
 }