1 files changed, 1 insertions, 1 deletions
diff --git a/emcc b/emcc
index f8d7319e..9e5de103 100755
--- a/emcc
+++ b/emcc
@@ -1231,7 +1231,7 @@ try:
         file_suffix = filename_type_suffix(input_file)
         if file_suffix.endswith(SOURCE_SUFFIXES):
           temp_file = temp_files[i]
-          logging.debug('optimizing %s with -O%d' % (input_file, llvm_opts))
+          logging.debug('optimizing %s with -O%s' % (input_file, llvm_opts))
           shared.Building.llvm_opt(temp_file, llvm_opts)
 
   # If we were just asked to generate bitcode, stop there