diff --git a/source/fs.c b/source/fs.c
index 3800abb..d49de60 100644
--- a/source/fs.c
+++ b/source/fs.c
@@ -105,7 +105,7 @@ u32 firmRead(void *dest)
     while(f_readdir(&dir, &info) == FR_OK && info.fname[0] != 0)
     {
         //Not a cxi
-        if(info.fname[9] != 'a') continue;
+        if(info.fname[9] != 'a' || strlen(info.fname) != 12) continue;
 
         //Multiple cxis were found
         if(firmVersion != 0xFFFFFFFF) ret = 1;