diff --git a/node.gyp b/node.gyp
index cb0036629e21a1..ed20a490d9ee1d 100644
--- a/node.gyp
+++ b/node.gyp
@@ -164,9 +164,9 @@
       [ 'OS=="win" and '
         'node_use_openssl=="true" and '
         'node_shared_openssl=="false"', {
-        'use_openssl_def': 1,
+        'use_openssl_def%': 1,
       }, {
-        'use_openssl_def': 0,
+        'use_openssl_def%': 0,
       }],
     ],
   },