diff --git a/src/fsck.c b/src/fsck.c
index dbb82c2..d8fe675 100644
--- a/src/fsck.c
+++ b/src/fsck.c
@@ -431,6 +431,9 @@ parse_opts (
                 bookmarkfs_opts_add(&info->handler_opts, opt);
                 break;
 
+              case '\0':
+                break;
+
               default:
                 return SUBOPT_ERR_BAD_KEY();
             }
diff --git a/src/mkfs.c b/src/mkfs.c
index 785e476..b36b891 100644
--- a/src/mkfs.c
+++ b/src/mkfs.c
@@ -92,7 +92,7 @@ parse_opts (
             char *opt = SUBOPT_STR;
             if (opt[0] == '@') {
                 bookmarkfs_opts_add(&ctx->backend_conf.opts, opt + 1);
-            } else {
+            } else if (opt[0] != '\0') {
                 return SUBOPT_ERR_BAD_KEY();
             }
         }
diff --git a/src/mount.c b/src/mount.c
index ce8ed52..c23a060 100644
--- a/src/mount.c
+++ b/src/mount.c
@@ -459,7 +459,7 @@ parse_opts (
             char *opt = SUBOPT_STR;
             if (opt[0] == '@') {
                 bookmarkfs_opts_add(&info->backend_conf.opts, opt + 1);
-            } else {
+            } else if (opt[0] != '\0') {
                 xassert(0 == fuse_opt_add_opt(&fargs->argv[1], opt));
             }
         }