diff --git a/swapoff.c b/swapoff.c
index 806d1f0..2d2b7ac 100644
--- a/swapoff.c
+++ b/swapoff.c
@@ -36,6 +36,8 @@ main(int argc, char *argv[])
 		FILE *fp;
 
 		fp = setmntent("/etc/fstab", "r");
+		if (!fp)
+			eprintf("setmntent %s:", "/etc/fstab");
 		while ((me = getmntent(fp)) != NULL) {
 			if (strcmp(me->mnt_type, MNTTYPE_SWAP) == 0) {
 				if (swapoff(me->mnt_fsname) < 0) {
diff --git a/swapon.c b/swapon.c
index 40e6c9f..6b3d32f 100644
--- a/swapon.c
+++ b/swapon.c
@@ -43,6 +43,8 @@ main(int argc, char *argv[])
 		FILE *fp;
 
 		fp = setmntent("/etc/fstab", "r");
+		if (!fp)
+			eprintf("setmntent %s:", "/etc/fstab");
 		while ((me = getmntent(fp)) != NULL) {
 			if (strcmp(me->mnt_type, MNTTYPE_SWAP) == 0
 			    && (hasmntopt(me, MNTOPT_NOAUTO) == NULL)) {