diff --git a/moshi-kotlin-codegen/src/main/java/com/squareup/moshi/kotlin/codegen/api/ProguardRules.kt b/moshi-kotlin-codegen/src/main/java/com/squareup/moshi/kotlin/codegen/api/ProguardRules.kt
index 4331c1d..b7cfb36 100644
--- a/moshi-kotlin-codegen/src/main/java/com/squareup/moshi/kotlin/codegen/api/ProguardRules.kt
+++ b/moshi-kotlin-codegen/src/main/java/com/squareup/moshi/kotlin/codegen/api/ProguardRules.kt
@@ -62,9 +62,23 @@ public data class ProguardConfig(
     if (!dontKeepClassNames)
       appendLine("-keepnames class $targetName")
 
-    // Keep the `JsonClass` annotation on the target class, R8 will shrink it away otherwise.
+    // Keep the `JsonClass` annotation on the target class, R8 will strip it away otherwise.
     appendLine("-keep${if (dontKeepClassNames) ",allowobfuscation" else ""} @com.squareup.moshi.JsonClass class *")
 
+    //
+    // -keepclassmembers enum * {
+    //    public static **[] values();
+    //    public static ** valueOf(java.lang.String);
+    //    public static <fields>;
+    // }
+    //
+    // Keep the enum values method, R8 will strip it away otherwise.
+    appendLine("-keepclassmembers enum * {")
+    appendLine("    public static **[] values();")
+    appendLine("    public static ** valueOf(java.lang.String);")
+    appendLine("    public static <fields>;")
+    appendLine("}")
+
     appendLine("-if class $targetName")
     appendLine("-${if (dontKeepClassNames) "keepclassmembers" else "keep"} class $adapterCanonicalName {")
     // Keep the constructor for Moshi's reflective lookup