diff --git a/app/proguard-rules.pro b/app/proguard-rules.pro
index f1b4245..8d9a55b 100644
--- a/app/proguard-rules.pro
+++ b/app/proguard-rules.pro
@@ -19,3 +19,17 @@
 # If you keep the line number information, uncomment this to
 # hide the original source file name.
 #-renamesourcefileattribute SourceFile
+
+# AndroidX Security delegates crypto operation to Tink which
+# depends on Protobuf Javalite. Recently Protobuf Javalite
+# introduced a change that relies on reflection, which doesn't
+# work with Proguard.
+# This rule keeps the (shaded) Protobuf classes in Tink as-is.
+# See also:
+# - https://github.com/google/tink/issues/361
+# - https://github.com/protocolbuffers/protobuf/issues/6463
+# - https://b.corp.google.com/issues/144631039
+-keep class * extends com.google.crypto.tink.shaded.protobuf.GeneratedMessageLite {
+  *;
+}
+