gcm_selftest depends on AES
diff --git a/library/gcm.c b/library/gcm.c
index 04e9d5b..a9e18c8 100644
--- a/library/gcm.c
+++ b/library/gcm.c
@@ -412,12 +412,12 @@
     memset( ctx, 0, sizeof( gcm_context ) );
 }
 
-#if defined(POLARSSL_SELF_TEST)
+#if defined(POLARSSL_SELF_TEST) && defined(POLARSSL_AES_C)
 
 #include <stdio.h>
 
 /*
- * GCM test vectors from:
+ * AES-GCM test vectors from:
  *
  * http://csrc.nist.gov/groups/STM/cavp/documents/mac/gcmtestvectors.zip
  */
@@ -850,6 +850,6 @@
 
 
 
-#endif
+#endif /* POLARSSL_SELF_TEST && POLARSSL_AES_C */
 
 #endif