1 files changed, 2 insertions, 0 deletions
diff --git a/util.c b/util.c
index 704ad89a6b..5aebe109fa 100644
--- a/util.c
+++ b/util.c
@@ -1827,6 +1827,8 @@ my_popen(char *cmd, char *mode)
     if (pid == 0) {
 	GV* tmpgv;
 
+#undef THIS
+#undef THAT
 #define THIS that
 #define THAT This
 	PerlLIO_close(p[THAT]);