diff --git a/src/core/gyp_run.pro b/src/core/gyp_run.pro
index dc22d14bf9486f30b8c30a7a00959b0cf8f7c571..f021d0724a9b6cdde1f96be188f8d09a39607d25 100644
--- a/src/core/gyp_run.pro
+++ b/src/core/gyp_run.pro
@@ -118,7 +118,7 @@ contains(WEBENGINE_CONFIG, use_appstore_compliant_code): GYP_CONFIG += appstore_
 
 # Compiling with -Os makes a huge difference in binary size, and the unwind tables is another big part,
 # but the latter are necessary for useful debug binaries.
-contains(WEBENGINE_CONFIG, reduce_binary_size): GYP_CONFIG += release_optimize=s debug_optimize=s release_unwind_tables=0
+contains(WEBENGINE_CONFIG, reduce_binary_size): GYP_CONFIG += release_optimize=s debug_optimize=s win_release_Optimization=1 release_unwind_tables=0
 
 !contains(WEBENGINE_CONFIG, use_spellchecker): {
     GYP_CONFIG += enable_spellcheck=0