diff --git a/tools/v8_gypfiles/v8.gyp b/tools/v8_gypfiles/v8.gyp
index b5ad9b0dcb03e2..4963d366ae10ae 100644
--- a/tools/v8_gypfiles/v8.gyp
+++ b/tools/v8_gypfiles/v8.gyp
@@ -1608,6 +1608,14 @@
     {
       'target_name': 'v8_zlib',
       'type': 'static_library',
+      'conditions': [
+        ['want_separate_host_toolset', {
+          'toolsets': ['host', 'target'],
+        }],
+        ['OS=="win"', {
+          'defines': ['X86_WINDOWS'],
+        }],
+      ],
       'direct_dependent_settings': {
         'include_dirs': [ '<(V8_ROOT)/third_party/zlib' ],
       },