2 files changed, 8 insertions, 0 deletions

diff --git a/src/s/freebsd.h b/src/s/freebsd.h
index 772a760900b..9a32b9bf57d 100644
--- a/src/s/freebsd.h
+++ b/src/s/freebsd.h
@@ -88,3 +88,7 @@
 #include <sys/wait.h>
 #endif
 #define WRETCODE(w) (_W_INT(w) >> 8)
+
+/* Needed to avoid hanging when child process writes an error message
+   and exits -- enami tsugutomo <enami@ba2.so-net.or.jp>.  */
+#define vfork fork
diff --git a/src/s/netbsd.h b/src/s/netbsd.h
index b6535665724..4ca4b4d6885 100644
--- a/src/s/netbsd.h
+++ b/src/s/netbsd.h
@@ -61,3 +61,7 @@
 #define NO_MATHERR
 
 #define AMPERSAND_FULL_NAME
+
+/* Needed to avoid hanging when child process writes an error message
+   and exits -- enami tsugutomo <enami@ba2.so-net.or.jp>.  */
+#define vfork fork