diff --git a/core/proguard.flags b/core/proguard.flags
index aa406b9..5148e56 100644
--- a/core/proguard.flags
+++ b/core/proguard.flags
@@ -38,6 +38,17 @@
   @com.android.internal.annotations.KeepForWeakReference <fields>;
 }
 
+# Needed to ensure callback field references are kept in their respective
+# owning classes when the downstream callback registrars only store weak refs.
+-if @com.android.internal.annotations.WeaklyReferencedCallback class *
+-keepclassmembers,allowaccessmodification class * {
+  <1> *;
+}
+-if class * extends @com.android.internal.annotations.WeaklyReferencedCallback **
+-keepclassmembers,allowaccessmodification class * {
+  <1> *;
+}
+
 # Understand the common @Keep annotation from various Android packages:
 #  * android.support.annotation
 #  * androidx.annotation