diff --git a/core/src/main/scala/org/apache/spark/internal/config/ConfigBuilder.scala b/core/src/main/scala/org/apache/spark/internal/config/ConfigBuilder.scala
index d87619afd3b2fbd68ef3f9c87e54d9a11f323339..b9921138cc6c71156d969b63a7ad0ee8c9e85171 100644
--- a/core/src/main/scala/org/apache/spark/internal/config/ConfigBuilder.scala
+++ b/core/src/main/scala/org/apache/spark/internal/config/ConfigBuilder.scala
@@ -225,6 +225,6 @@ private[spark] case class ConfigBuilder(key: String) {
   }
 
   def regexConf: TypedConfigBuilder[Regex] = {
-    new TypedConfigBuilder(this, regexFromString(_, this.key), _.regex)
+    new TypedConfigBuilder(this, regexFromString(_, this.key), _.toString)
   }
 }
diff --git a/core/src/test/scala/org/apache/spark/internal/config/ConfigEntrySuite.scala b/core/src/test/scala/org/apache/spark/internal/config/ConfigEntrySuite.scala
index f3756b21080b2a0fd3caa60688b6504a63ec27cb..3ff7e84d73bd4f791ae7bdc6e8861ae349d9538b 100644
--- a/core/src/test/scala/org/apache/spark/internal/config/ConfigEntrySuite.scala
+++ b/core/src/test/scala/org/apache/spark/internal/config/ConfigEntrySuite.scala
@@ -100,10 +100,10 @@ class ConfigEntrySuite extends SparkFunSuite {
     val rConf = ConfigBuilder(testKey("regex")).regexConf.createWithDefault(".*".r)
 
     conf.set(rConf, "[0-9a-f]{8}".r)
-    assert(conf.get(rConf).regex === "[0-9a-f]{8}")
+    assert(conf.get(rConf).toString === "[0-9a-f]{8}")
 
     conf.set(rConf.key, "[0-9a-f]{4}")
-    assert(conf.get(rConf).regex === "[0-9a-f]{4}")
+    assert(conf.get(rConf).toString === "[0-9a-f]{4}")
 
     conf.set(rConf.key, "[.")
     val e = intercept[IllegalArgumentException](conf.get(rConf))