diff --git a/common/util.c b/common/util.c
index b72f61836..830b48a72 100644
--- a/common/util.c
+++ b/common/util.c
@@ -24,6 +24,7 @@
 #include <sys/wait.h>
 #include <unistd.h>
 #include <limits.h>
+#include <fcntl.h>
 
 #include "util.h"
 #include "tokenize.h"
@@ -273,4 +274,18 @@ a_strsplit(const char *str, ssize_t len, char delim)
     return retval;
 }
 
+/** Mark a file descriptor as close-on-exec.
+ * \param fd The file descriptor.
+ * \return The fcntl() return value.
+ */
+int
+fd_set_close_on_exec(int fd)
+{
+    int flags = fcntl(fd, F_GETFD, 0);
+    /* ignore errors */
+    if(flags < 0)
+        return flags;
+    return fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
+}
+
 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=80
diff --git a/common/util.h b/common/util.h
index 7869a9692..a3efbd336 100644
--- a/common/util.h
+++ b/common/util.h
@@ -339,6 +339,7 @@ void *name_func_lookup(const char *, size_t, const name_func_link_t *);
 const char * name_func_rlookup(void *, const name_func_link_t *);
 void a_exec(const char *);
 char ** a_strsplit(const char *, ssize_t, char);
+int fd_set_close_on_exec(int);
 
 #define a_asprintf(strp, fmt, ...) \
     do { \