diff --git a/library/x509_csr.c b/library/x509_csr.c
index 7213fd2..16e212b 100644
--- a/library/x509_csr.c
+++ b/library/x509_csr.c
@@ -129,7 +129,7 @@
         return( ret );
     }
     else
-#endif
+#endif /* POLARSSL_PEM_PARSE_C */
     {
         /*
          * nope, copy the raw DER data
@@ -332,7 +332,7 @@
 }
 
 #define snprintf compat_snprintf
-#endif
+#endif /* _MSC_VER && !snprintf && !EFIX64 && !EFI32 */
 
 #define POLARSSL_ERR_DEBUG_BUF_TOO_SMALL    -2