diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalog.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalog.scala
index 053ba836f212c..6f6bd62ff8707 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalog.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalog.scala
@@ -1344,8 +1344,8 @@ class SessionCatalog(
   /**
    * Unregister a temporary or permanent function from a session-specific [[FunctionRegistry]]
    */
-  def unregisterFunction(name: FunctionIdentifier, ignoreIfNotExists: Boolean): Unit = {
-    if (!functionRegistry.dropFunction(name) && !ignoreIfNotExists) {
+  def unregisterFunction(name: FunctionIdentifier): Unit = {
+    if (!functionRegistry.dropFunction(name)) {
       throw new NoSuchFunctionException(
         formatDatabaseName(name.database.getOrElse(currentDb)), name.funcName)
     }
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/command/functions.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/command/functions.scala
index c63d214caba0f..73dde4cad0c86 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/command/functions.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/command/functions.scala
@@ -267,7 +267,7 @@ case class RefreshFunctionCommand(
       catalog.registerFunction(func, true)
     } else if (catalog.isRegisteredFunction(identifier)) {
       // clear cached function.
-      catalog.unregisterFunction(identifier, true)
+      catalog.unregisterFunction(identifier)
     } else {
       throw new NoSuchFunctionException(identifier.database.get, functionName)
     }