diff --git a/ui/build/Android.bp b/ui/build/Android.bp
index 8f5250b..25520da 100644
--- a/ui/build/Android.bp
+++ b/ui/build/Android.bp
@@ -30,6 +30,7 @@
         "kati.go",
         "make.go",
         "ninja.go",
+        "proc_sync.go",
         "signal.go",
         "soong.go",
         "util.go",
@@ -37,6 +38,7 @@
     testSrcs: [
         "environment_test.go",
         "util_test.go",
+        "proc_sync_test.go",
     ],
     darwin: {
         srcs: [