diff --git a/CHANGELOG b/CHANGELOG
index b28b46ca..876fd078 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,7 @@
+Version 3.1.1 (2025-01-23)
+--------------------------
+Fix GTMSS preview expired message handling
+
 Version 3.1.0 (2025-01-20)
 --------------------------
 Change License to SLULA 1.1
diff --git a/README.md b/README.md
index 7a72b455..c0745172 100644
--- a/README.md
+++ b/README.md
@@ -18,5 +18,5 @@ The AWS-specific distribution contains everything, including the Kinesis source,
 
 To comply with the [Amazon Software License](https://github.com/twitchscience/kinsumer/blob/master/LICENSE), you may only use this distribution of Snowbridge _“with the web services, computing platforms or applications provided by Amazon.com, Inc. or its affiliates, including Amazon Web Services, Inc.”_
 
-[release-image]: http://img.shields.io/badge/golang-3.1.0-6ad7e5.svg?style=flat
+[release-image]: http://img.shields.io/badge/golang-3.1.1-6ad7e5.svg?style=flat
 [releases]: https://github.com/snowplow/snowbridge/releases/
diff --git a/VERSION b/VERSION
index fd2a0186..94ff29cc 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-3.1.0
+3.1.1
diff --git a/cmd/constants.go b/cmd/constants.go
index 6dc59f5e..d5cda466 100644
--- a/cmd/constants.go
+++ b/cmd/constants.go
@@ -13,7 +13,7 @@ package cmd
 
 const (
 	// AppVersion is the current version of the app
-	AppVersion = "3.1.0"
+	AppVersion = "3.1.1"
 
 	// AppName is the name of the application to use in logging / places that require the artifact
 	AppName = "snowbridge"
diff --git a/pkg/transform/snowplow_gtmss_preview.go b/pkg/transform/snowplow_gtmss_preview.go
index e2556dd4..8c6dfbe8 100644
--- a/pkg/transform/snowplow_gtmss_preview.go
+++ b/pkg/transform/snowplow_gtmss_preview.go
@@ -77,25 +77,26 @@ func gtmssPreviewTransformation(ctx, property, headerKey string, expiry time.Dur
 			return nil, nil, message, nil
 		}
 
-		tstamp, err := parsedEvent.GetValue("collector_tstamp")
+		headerVal, err := extractHeaderValue(parsedEvent, ctx, property)
 		if err != nil {
 			message.SetError(err)
 			return nil, nil, message, nil
 		}
 
-		if collectorTstamp, ok := tstamp.(time.Time); ok {
-			if time.Now().UTC().After(collectorTstamp.Add(expiry)) {
-				message.SetError(errors.New("Message has expired"))
+		if headerVal != nil {
+			tstamp, err := parsedEvent.GetValue("collector_tstamp")
+			if err != nil {
+				message.SetError(err)
 				return nil, nil, message, nil
 			}
-		}
 
-		headerVal, err := extractHeaderValue(parsedEvent, ctx, property)
-		if err != nil {
-			message.SetError(err)
-			return nil, nil, message, nil
-		}
-		if headerVal != nil {
+			if collectorTstamp, ok := tstamp.(time.Time); ok {
+				if time.Now().UTC().After(collectorTstamp.Add(expiry)) {
+					message.SetError(errors.New("Message has expired"))
+					return nil, nil, message, nil
+				}
+			}
+
 			if message.HTTPHeaders == nil {
 				message.HTTPHeaders = make(map[string]string)
 			}
diff --git a/pkg/transform/snowplow_gtmss_preview_test.go b/pkg/transform/snowplow_gtmss_preview_test.go
index 02b8c832..ffcd160a 100644
--- a/pkg/transform/snowplow_gtmss_preview_test.go
+++ b/pkg/transform/snowplow_gtmss_preview_test.go
@@ -69,7 +69,7 @@ func TestGTMSSPreview(t *testing.T) {
 			Ctx:       "contexts_com_google_tag-manager_server-side_preview_mode_1",
 			Property:  "x-gtm-server-preview",
 			HeaderKey: "x-gtm-server-preview",
-			Expiry:    fiftyYears,
+			Expiry:    1 * time.Hour,
 			InputMsg: &models.Message{
 				Data:         spTsvNoGtmss,
 				PartitionKey: "pk",