1 files changed, 3 insertions, 0 deletions

diff --git a/src/process.c b/src/process.c
index fbe3ae69329..77c9e857c04 100644
--- a/src/process.c
+++ b/src/process.c
@@ -598,6 +598,9 @@ setup_process_coding_systems (process)
   int inch = XINT (p->infd);
   int outch = XINT (p->outfd);
 
+  if (inch < 0 || outch < 0)
+    return;
+
   if (!proc_decode_coding_system[inch])
     proc_decode_coding_system[inch]
       = (struct coding_system *) xmalloc (sizeof (struct coding_system));