diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7165322d60f..4372aea58f4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -76,6 +76,7 @@ Here is an overview of all new **experimental** features:
 - **General**: Fix CVE-2023-39325 in golang.org/x/net ([#5122](https://github.com/kedacore/keda/issues/5122))
 - **General**: Prevented stuck status due to timeouts during scalers generation ([#5083](https://github.com/kedacore/keda/issues/5083))
 - **Azure Pipelines**: No more HTTP 400 errors produced by poolName with spaces ([#5107](https://github.com/kedacore/keda/issues/5107))
+- **GCP pubsub scaler**: Missing use of default value of `value` added ([#5093](https://github.com/kedacore/keda/issues/5093))
 - **ScaledJobs**: Copy ScaledJob annotations to child Jobs ([#4594](https://github.com/kedacore/keda/issues/4594))
 
 ### Deprecations
diff --git a/pkg/scalers/gcp_pubsub_scaler.go b/pkg/scalers/gcp_pubsub_scaler.go
index 5a3c2cd9da5..6aa56adf559 100644
--- a/pkg/scalers/gcp_pubsub_scaler.go
+++ b/pkg/scalers/gcp_pubsub_scaler.go
@@ -65,7 +65,7 @@ func NewPubSubScaler(config *ScalerConfig) (Scaler, error) {
 
 func parsePubSubMetadata(config *ScalerConfig, logger logr.Logger) (*pubsubMetadata, error) {
 	// set subscription size to the default mode
-	meta := pubsubMetadata{mode: pubSubModeSubscriptionSize}
+	meta := pubsubMetadata{mode: pubSubModeSubscriptionSize, value: pubSubDefaultValue}
 
 	mode, modePresent := config.TriggerMetadata["mode"]
 	value, valuePresent := config.TriggerMetadata["value"]
@@ -83,7 +83,6 @@ func parsePubSubMetadata(config *ScalerConfig, logger logr.Logger) (*pubsubMetad
 	} else {
 		if modePresent {
 			meta.mode = mode
-			meta.value = pubSubDefaultValue
 		}
 
 		if valuePresent {
diff --git a/pkg/scalers/gcp_pubsub_scaler_test.go b/pkg/scalers/gcp_pubsub_scaler_test.go
index 2b4d724a49f..19ddbf7abfc 100644
--- a/pkg/scalers/gcp_pubsub_scaler_test.go
+++ b/pkg/scalers/gcp_pubsub_scaler_test.go
@@ -58,6 +58,10 @@ var testPubSubMetadata = []parsePubSubMetadataTestData{
 	{nil, map[string]string{"subscriptionName": "projects/myproject/mysubscription", "subscriptionSize": "7", "credentialsFromEnv": "SAMPLE_CREDS"}, false},
 	// properly formed float value and activationTargetValue
 	{nil, map[string]string{"subscriptionName": "mysubscription", "value": "7.1", "credentialsFromEnv": "SAMPLE_CREDS", "activationValue": "2.1"}, false},
+	// All optional omitted
+	{nil, map[string]string{"subscriptionName": "mysubscription", "credentialsFromEnv": "SAMPLE_CREDS"}, false},
+	// value omittted when mode present
+	{nil, map[string]string{"subscriptionName": "mysubscription", "mode": "SubscriptionSize", "credentialsFromEnv": "SAMPLE_CREDS"}, false},
 }
 
 var gcpPubSubMetricIdentifiers = []gcpPubSubMetricIdentifier{
@@ -70,6 +74,11 @@ var gcpSubscriptionNameTests = []gcpPubSubSubscription{
 	{&testPubSubMetadata[12], 1, "projects/myproject/mysubscription", ""},
 }
 
+var gcpSubscriptionDefaults = []gcpPubSubSubscription{
+	{&testPubSubMetadata[14], 0, "", ""},
+	{&testPubSubMetadata[15], 0, "", ""},
+}
+
 func TestPubSubParseMetadata(t *testing.T) {
 	for _, testData := range testPubSubMetadata {
 		_, err := parsePubSubMetadata(&ScalerConfig{AuthParams: testData.authParams, TriggerMetadata: testData.metadata, ResolvedEnv: testPubSubResolvedEnv}, logr.Discard())
@@ -82,6 +91,21 @@ func TestPubSubParseMetadata(t *testing.T) {
 	}
 }
 
+func TestPubSubMetadataDefaultValues(t *testing.T) {
+	for _, testData := range gcpSubscriptionDefaults {
+		metaData, err := parsePubSubMetadata(&ScalerConfig{AuthParams: testData.metadataTestData.authParams, TriggerMetadata: testData.metadataTestData.metadata, ResolvedEnv: testPubSubResolvedEnv}, logr.Discard())
+		if err != nil {
+			t.Error("Expected success but got error", err)
+		}
+		if pubSubModeSubscriptionSize != metaData.mode {
+			t.Errorf(`Expected mode "%s" but got "%s"`, pubSubModeSubscriptionSize, metaData.mode)
+		}
+		if pubSubDefaultValue != metaData.value {
+			t.Errorf(`Expected value "%d" but got "%f"`, pubSubDefaultValue, metaData.value)
+		}
+	}
+}
+
 func TestGcpPubSubGetMetricSpecForScaling(t *testing.T) {
 	for _, testData := range gcpPubSubMetricIdentifiers {
 		meta, err := parsePubSubMetadata(&ScalerConfig{TriggerMetadata: testData.metadataTestData.metadata, ResolvedEnv: testPubSubResolvedEnv, ScalerIndex: testData.scalerIndex}, logr.Discard())