diff --git a/third_party/third_party.gni b/third_party/third_party.gni
index 37b1e03..dd9f057 100644
--- a/third_party/third_party.gni
+++ b/third_party/third_party.gni
@@ -5,6 +5,9 @@
 
 template("third_party") {
   config(target_name + "_public") {
+    if (defined(invoker.public_defines)) {
+      defines = invoker.public_defines
+    }
     include_dirs = invoker.public_include_dirs
   }
   source_set(target_name) {