diff --git a/CHANGELOG b/CHANGELOG
index 06e5479..1fc079b 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -45,6 +45,7 @@ xx/xx/2018 autofs-5.1.5
 - move close stdio descriptors to become_daemon().
 - add systemd service command line option.
 - support strictexpire mount option.
+- add NULL check for get_addr_string() return.
 
 19/12/2017 autofs-5.1.4
 - fix spec file url.
diff --git a/modules/mount_nfs.c b/modules/mount_nfs.c
index 426c27b..295c4a5 100644
--- a/modules/mount_nfs.c
+++ b/modules/mount_nfs.c
@@ -333,7 +333,13 @@ dont_probe:
 			socklen_t len = INET6_ADDRSTRLEN;
 			char n_buf[len + 1];
 			const char *n_addr;
+
 			n_addr = get_addr_string(this->addr, n_buf, len);
+			if (!n_addr) {
+				char *estr = strerror_r(errno, buf, MAX_ERR_BUF);
+				error(ap->logopt, "get_addr_string: %s", estr);
+				goto forced_fail;
+			}
 			loc = malloc(strlen(n_addr) + strlen(this->path) + 4);
 			if (!loc) {
 				char *estr = strerror_r(errno, buf, MAX_ERR_BUF);