diff --git a/common/framework/com/android/net/module/util/ConnectivitySettingsUtils.java b/common/framework/com/android/net/module/util/ConnectivitySettingsUtils.java
index b7eb70b..f4856b3 100644
--- a/common/framework/com/android/net/module/util/ConnectivitySettingsUtils.java
+++ b/common/framework/com/android/net/module/util/ConnectivitySettingsUtils.java
@@ -60,6 +60,10 @@
     }
 
     private static int getPrivateDnsModeAsInt(String mode) {
+        // If both PRIVATE_DNS_MODE and PRIVATE_DNS_DEFAULT_MODE are not set, choose
+        // PRIVATE_DNS_MODE_OPPORTUNISTIC as default mode.
+        if (TextUtils.isEmpty(mode))
+            return PRIVATE_DNS_MODE_OPPORTUNISTIC;
         switch (mode) {
             case "off":
                 return PRIVATE_DNS_MODE_OFF;
@@ -68,7 +72,10 @@
             case "opportunistic":
                 return PRIVATE_DNS_MODE_OPPORTUNISTIC;
             default:
-                throw new IllegalArgumentException("Invalid private dns mode: " + mode);
+                // b/260211513: adb shell settings put global private_dns_mode foo
+                // can result in arbitrary strings - treat any unknown value as empty string.
+                // throw new IllegalArgumentException("Invalid private dns mode: " + mode);
+                return PRIVATE_DNS_MODE_OPPORTUNISTIC;
         }
     }
 
@@ -82,9 +89,6 @@
         final ContentResolver cr = context.getContentResolver();
         String mode = Settings.Global.getString(cr, PRIVATE_DNS_MODE);
         if (TextUtils.isEmpty(mode)) mode = Settings.Global.getString(cr, PRIVATE_DNS_DEFAULT_MODE);
-        // If both PRIVATE_DNS_MODE and PRIVATE_DNS_DEFAULT_MODE are not set, choose
-        // PRIVATE_DNS_MODE_OPPORTUNISTIC as default mode.
-        if (TextUtils.isEmpty(mode)) return PRIVATE_DNS_MODE_OPPORTUNISTIC;
         return getPrivateDnsModeAsInt(mode);
     }