diff --git a/common/iobuf.c b/common/iobuf.c
index 3c68ce59c..badbf78da 100644
--- a/common/iobuf.c
+++ b/common/iobuf.c
@@ -1301,7 +1301,7 @@ iobuf_open (const char *fname)
   iobuf_t a;
   gnupg_fd_t fp;
   file_filter_ctx_t *fcx;
-  size_t len;
+  size_t len = 0;
   int print_only = 0;
   int fd;