diff --git a/packages/SystemUI/shared/Android.bp b/packages/SystemUI/shared/Android.bp
index 18bd6b4..f59a320 100644
--- a/packages/SystemUI/shared/Android.bp
+++ b/packages/SystemUI/shared/Android.bp
@@ -59,6 +59,9 @@
     resource_dirs: [
         "res",
     ],
+    optimize: {
+        proguard_flags_files: ["proguard.flags"],
+    },
     java_version: "1.8",
     min_sdk_version: "current",
     plugins: ["dagger2-compiler"],
diff --git a/packages/SystemUI/shared/proguard.flags b/packages/SystemUI/shared/proguard.flags
new file mode 100644
index 0000000..5eda045
--- /dev/null
+++ b/packages/SystemUI/shared/proguard.flags
@@ -0,0 +1,4 @@
+# Retain signatures of TypeToken and its subclasses for gson usage in ClockRegistry
+-keepattributes Signature
+-keep,allowobfuscation,allowshrinking class com.google.gson.reflect.TypeToken
+-keep,allowobfuscation,allowshrinking class * extends com.google.gson.reflect.TypeToken
\ No newline at end of file