diff --git a/common.gypi b/common.gypi
index f198d331296..ce556fb43ab 100644
--- a/common.gypi
+++ b/common.gypi
@@ -45,6 +45,9 @@
             'LinkIncremental': 2, # enable incremental linking
           },
         },
+        'xcode_settings': {
+          'GCC_OPTIMIZATION_LEVEL': '0', # stop gyp from defaulting to -Os
+        },
       },
       'Release': {
         'conditions': [