diff --git a/src/tweetnacl.c b/src/tweetnacl.c
index 0520131b..16f61af5 100644
--- a/src/tweetnacl.c
+++ b/src/tweetnacl.c
@@ -30,8 +30,10 @@
 #include "platform.hpp"
 #if defined (ZMQ_USE_TWEETNACL)
 
-//  Disable warnings for this source only, rather than for the whole
-//  codebase when building with C99 or with Microsoft's compiler
+/*
+    Disable warnings for this source only, rather than for the whole
+    codebase when building with C99 or with Microsoft's compiler
+*/
 #if defined __GNUC__ && __STDC_VERSION__ < 201112L
 #   pragma GCC diagnostic ignored "-Wsign-compare"
 #elif defined _MSC_VER