diff --git a/gravityforms-multiple-form-instances.php b/gravityforms-multiple-form-instances.php
index 02ecc7a..d232504 100644
--- a/gravityforms-multiple-form-instances.php
+++ b/gravityforms-multiple-form-instances.php
@@ -26,6 +26,7 @@ class Gravity_Forms_Multiple_Form_Instances {
 	public function __construct() {
 		// hook the HTML ID string find & replace functionality
 		add_filter( 'gform_get_form_filter', array( $this, 'gform_get_form_filter' ), 10, 2 );
+		add_filter( 'gform_confirmation', array( $this, 'gform_get_form_filter' ), 10, 2 );
 	}
 
 	/**
diff --git a/tests/unit-tests/GFMFI_ConstructTest.php b/tests/unit-tests/GFMFI_ConstructTest.php
index 4e016e4..8bb6abe 100644
--- a/tests/unit-tests/GFMFI_ConstructTest.php
+++ b/tests/unit-tests/GFMFI_ConstructTest.php
@@ -19,4 +19,13 @@ public function testHookRegistered() {
 		$this->assertSame( 10, has_filter( 'gform_get_form_filter', array( $this->gfmfi, 'gform_get_form_filter' ) ) );
 	}
 
+	/**
+	 * @covers Gravity_Forms_Multiple_Form_Instances::__construct
+	 */
+	public function testHookGformConfirmationRegistered() {
+		$this->gfmfi->__construct();
+
+		$this->assertSame( 10, has_filter( 'gform_confirmation', array( $this->gfmfi, 'gform_get_form_filter' ) ) );
+	}
+
 }
\ No newline at end of file