diff --git a/src/fs.c b/src/fs.c
index b2c3fe0..e540d02 100644
--- a/src/fs.c
+++ b/src/fs.c
@@ -1029,7 +1029,17 @@ int fs_open(void *d)
 		return 0;
 	}
 
-	fs_file_descriptions[free_fd].inode = rp.target_inode_ptr;
+	{
+		struct fs_inode i;
+		read_block(read_inode_ptr(rp.target_inode_ptr), &i);
+
+		if (i.ftype == DIRECTORY) {
+			pr_err("can't open '%s': file is a directory\n", rp.target_fname);
+			return 0;
+		}
+	}
+
+	fs_file_descriptions[free_fd].inode = read_inode_ptr(rp.target_inode_ptr);
 	fs_file_descriptions[free_fd].rw_offset = 0;
 
 	pr_stdout("%d\n", free_fd);