diff --git a/libfreefare/freefare.h b/libfreefare/freefare.h
index 85b79c6..b03ece2 100644
--- a/libfreefare/freefare.h
+++ b/libfreefare/freefare.h
@@ -171,7 +171,7 @@ void		 mad_free (Mad mad);
 MifareClassicSectorNumber *mifare_application_alloc (Mad mad, const MadAid aid, const size_t size);
 ssize_t		 mifare_application_read (MifareTag tag, Mad mad, const MadAid aid, void *buf, size_t nbytes, const MifareClassicKey key, const MifareClassicKeyType key_type);
 ssize_t		 mifare_application_write (MifareTag tag, Mad mad, const MadAid aid, const void *buf, size_t nbytes, const MifareClassicKey key, const MifareClassicKeyType key_type);
-void		 mifare_application_free (Mad mad, const MadAid aid);
+int		 mifare_application_free (Mad mad, const MadAid aid);
 
 MifareClassicSectorNumber *mifare_application_find (Mad mad, const MadAid aid);
 
diff --git a/libfreefare/mifare_application.c b/libfreefare/mifare_application.c
index 50e905f..b18d4b8 100644
--- a/libfreefare/mifare_application.c
+++ b/libfreefare/mifare_application.c
@@ -158,18 +158,24 @@ mifare_application_alloc (Mad mad, MadAid aid, size_t size)
 /*
  * Remove an application from a MAD.
  */
-void
+int
 mifare_application_free (Mad mad, MadAid aid)
 {
     MifareClassicSectorNumber *sectors = mifare_application_find (mad, aid);
     MifareClassicSectorNumber *p = sectors;
     MadAid free_aid = { 0x00, 0x00 };
+
+    /* figure out if malloc() in mifare_application_find() failed */
+    if (sectors == NULL) return count_aids (mad, aid) ? -1 : 0;
+
     while (*p) {
 	mad_set_aid (mad, *p, free_aid);
 	p++;
     }
 
     free (sectors);
+
+    return 0;
 }