1 files changed, 1 insertions, 1 deletions
diff --git a/emcc b/emcc
index 6191d1f5..ece1e4c5 100755
--- a/emcc
+++ b/emcc
@@ -1222,7 +1222,7 @@ try:
     assert not shared.Settings.PGO, 'cannot run PGO in ASM_JS mode'
 
     if shared.Settings.SAFE_HEAP and not js_opts:
-      logging.warning('asm.js+SAFE_HEAP requires js opts to be run (-O1 or above by default)')
+      logging.warning('asm.js+SAFE_HEAP requires js opts to be run to be fully effective (-O2 or above by default)')
 
     if shared.Settings.ALLOW_MEMORY_GROWTH:
       logging.error('Cannot enable ALLOW_MEMORY_GROWTH with asm.js, build with -s ASM_JS=0 if you need a growable heap');