diff --git a/library/pk_wrap.c b/library/pk_wrap.c
index 33253a4..6983d14 100644
--- a/library/pk_wrap.c
+++ b/library/pk_wrap.c
@@ -996,7 +996,7 @@
     return( 0 );
 }
 
-#endif
+#endif /* MBEDTLS_ECDSA_C */
 
 static int pk_opaque_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
                    const unsigned char *hash, size_t hash_len,