diff --git a/core-api/src/main/java/com/optimizely/ab/notification/DecisionNotification.java b/core-api/src/main/java/com/optimizely/ab/notification/DecisionNotification.java
index 57cce0fe2..1bcb88599 100644
--- a/core-api/src/main/java/com/optimizely/ab/notification/DecisionNotification.java
+++ b/core-api/src/main/java/com/optimizely/ab/notification/DecisionNotification.java
@@ -177,7 +177,7 @@ public DecisionNotification build() {
             decisionInfo = new HashMap<>();
             decisionInfo.put(FEATURE_KEY, featureKey);
             decisionInfo.put(FEATURE_ENABLED, featureEnabled);
-            decisionInfo.put(SOURCE, source);
+            decisionInfo.put(SOURCE, source.toString());
 
             Map<String, String> sourceInfo = new HashMap<>();
             if (source.equals(FeatureDecision.DecisionSource.FEATURE_TEST)) {
@@ -274,9 +274,9 @@ public DecisionNotification build() {
             if (featureDecision != null && FeatureDecision.DecisionSource.FEATURE_TEST.equals(featureDecision.decisionSource)) {
                 sourceInfo.put(EXPERIMENT_KEY, featureDecision.experiment.getKey());
                 sourceInfo.put(VARIATION_KEY, featureDecision.variation.getKey());
-                decisionInfo.put(SOURCE, featureDecision.decisionSource);
+                decisionInfo.put(SOURCE, featureDecision.decisionSource.toString());
             } else {
-                decisionInfo.put(SOURCE, FeatureDecision.DecisionSource.ROLLOUT);
+                decisionInfo.put(SOURCE, FeatureDecision.DecisionSource.ROLLOUT.toString());
             }
             decisionInfo.put(SOURCE_INFO, sourceInfo);
 
diff --git a/core-api/src/test/java/com/optimizely/ab/OptimizelyTest.java b/core-api/src/test/java/com/optimizely/ab/OptimizelyTest.java
index d7f486e50..ab81c6cd1 100644
--- a/core-api/src/test/java/com/optimizely/ab/OptimizelyTest.java
+++ b/core-api/src/test/java/com/optimizely/ab/OptimizelyTest.java
@@ -2890,7 +2890,7 @@ public void isFeatureEnabledWithListenerUserInExperimentFeatureOn() throws Excep
         final Map<String, Object> testDecisionInfoMap = new HashMap<>();
         testDecisionInfoMap.put(FEATURE_KEY, validFeatureKey);
         testDecisionInfoMap.put(FEATURE_ENABLED, true);
-        testDecisionInfoMap.put(SOURCE, FeatureDecision.DecisionSource.FEATURE_TEST);
+        testDecisionInfoMap.put(SOURCE, FeatureDecision.DecisionSource.FEATURE_TEST.toString());
         testDecisionInfoMap.put(SOURCE_INFO, testSourceInfo);
 
         int notificationId = optimizely.notificationCenter.addDecisionNotificationListener(
@@ -2946,7 +2946,7 @@ public void isFeatureEnabledWithListenerUserInExperimentFeatureOff() throws Exce
         final Map<String, Object> testDecisionInfoMap = new HashMap<>();
         testDecisionInfoMap.put(FEATURE_KEY, validFeatureKey);
         testDecisionInfoMap.put(FEATURE_ENABLED, false);
-        testDecisionInfoMap.put(SOURCE, FeatureDecision.DecisionSource.FEATURE_TEST);
+        testDecisionInfoMap.put(SOURCE, FeatureDecision.DecisionSource.FEATURE_TEST.toString());
         testDecisionInfoMap.put(SOURCE_INFO, testSourceInfo);
 
         int notificationId = optimizely.notificationCenter.addDecisionNotificationListener(
@@ -3002,7 +3002,7 @@ public void isFeatureEnabledWithListenerUserNotInExperimentAndNotInRollOut() thr
         final Map<String, Object> testDecisionInfoMap = new HashMap<>();
         testDecisionInfoMap.put(FEATURE_KEY, validFeatureKey);
         testDecisionInfoMap.put(FEATURE_ENABLED, false);
-        testDecisionInfoMap.put(SOURCE, FeatureDecision.DecisionSource.ROLLOUT);
+        testDecisionInfoMap.put(SOURCE, FeatureDecision.DecisionSource.ROLLOUT.toString());
         testDecisionInfoMap.put(SOURCE_INFO, new HashMap<>());
 
         int notificationId = optimizely.notificationCenter.addDecisionNotificationListener(
@@ -3049,7 +3049,7 @@ public void isFeatureEnabledWithListenerUserInRollOut() throws Exception {
         testDecisionInfoMap.put(VARIATION_KEY, null);
         testDecisionInfoMap.put(FEATURE_KEY, validFeatureKey);
         testDecisionInfoMap.put(FEATURE_ENABLED, true);
-        testDecisionInfoMap.put(SOURCE, FeatureDecision.DecisionSource.ROLLOUT);
+        testDecisionInfoMap.put(SOURCE, FeatureDecision.DecisionSource.ROLLOUT.toString());
         testDecisionInfoMap.put(SOURCE_INFO, new HashMap<>());
 
         int notificationId = optimizely.notificationCenter.addDecisionNotificationListener(
@@ -3104,7 +3104,7 @@ public void getFeatureVariableWithListenerUserInExperimentFeatureOn() throws Exc
         testDecisionInfoMap.put(VARIABLE_KEY, validVariableKey);
         testDecisionInfoMap.put(VARIABLE_TYPE, FeatureVariable.VariableType.STRING);
         testDecisionInfoMap.put(VARIABLE_VALUE, expectedValue);
-        testDecisionInfoMap.put(SOURCE, FeatureDecision.DecisionSource.FEATURE_TEST);
+        testDecisionInfoMap.put(SOURCE, FeatureDecision.DecisionSource.FEATURE_TEST.toString());
         testDecisionInfoMap.put(SOURCE_INFO, testSourceInfo);
 
         int notificationId = optimizely.notificationCenter.addDecisionNotificationListener(
@@ -3157,7 +3157,7 @@ public void getFeatureVariableWithListenerUserInExperimentFeatureOff() {
         testDecisionInfoMap.put(VARIABLE_KEY, validVariableKey);
         testDecisionInfoMap.put(VARIABLE_TYPE, FeatureVariable.VariableType.STRING);
         testDecisionInfoMap.put(VARIABLE_VALUE, expectedValue);
-        testDecisionInfoMap.put(SOURCE, FeatureDecision.DecisionSource.FEATURE_TEST);
+        testDecisionInfoMap.put(SOURCE, FeatureDecision.DecisionSource.FEATURE_TEST.toString());
         testDecisionInfoMap.put(SOURCE_INFO, testSourceInfo);
 
         int notificationId = optimizely.notificationCenter.addDecisionNotificationListener(
@@ -3207,7 +3207,7 @@ public void getFeatureVariableWithListenerUserInRollOutFeatureOn() throws Except
         testDecisionInfoMap.put(VARIABLE_KEY, validVariableKey);
         testDecisionInfoMap.put(VARIABLE_TYPE, FeatureVariable.VariableType.STRING);
         testDecisionInfoMap.put(VARIABLE_VALUE, expectedValue);
-        testDecisionInfoMap.put(SOURCE, FeatureDecision.DecisionSource.ROLLOUT);
+        testDecisionInfoMap.put(SOURCE, FeatureDecision.DecisionSource.ROLLOUT.toString());
         testDecisionInfoMap.put(SOURCE_INFO, Collections.EMPTY_MAP);
 
         int notificationId = optimizely.notificationCenter.addDecisionNotificationListener(
@@ -3257,7 +3257,7 @@ public void getFeatureVariableWithListenerUserNotInRollOutFeatureOff() {
         testDecisionInfoMap.put(VARIABLE_KEY, validVariableKey);
         testDecisionInfoMap.put(VARIABLE_TYPE, FeatureVariable.VariableType.BOOLEAN);
         testDecisionInfoMap.put(VARIABLE_VALUE, expectedValue);
-        testDecisionInfoMap.put(SOURCE, FeatureDecision.DecisionSource.ROLLOUT);
+        testDecisionInfoMap.put(SOURCE, FeatureDecision.DecisionSource.ROLLOUT.toString());
         testDecisionInfoMap.put(SOURCE_INFO, Collections.EMPTY_MAP);
 
         int notificationId = optimizely.notificationCenter.addDecisionNotificationListener(
@@ -3306,7 +3306,7 @@ public void getFeatureVariableIntegerWithListenerUserInRollOutFeatureOn() {
         testDecisionInfoMap.put(VARIABLE_KEY, validVariableKey);
         testDecisionInfoMap.put(VARIABLE_TYPE, FeatureVariable.VariableType.INTEGER);
         testDecisionInfoMap.put(VARIABLE_VALUE, expectedValue);
-        testDecisionInfoMap.put(SOURCE, FeatureDecision.DecisionSource.ROLLOUT);
+        testDecisionInfoMap.put(SOURCE, FeatureDecision.DecisionSource.ROLLOUT.toString());
         testDecisionInfoMap.put(SOURCE_INFO, Collections.EMPTY_MAP);
 
         int notificationId = optimizely.notificationCenter.addDecisionNotificationListener(
@@ -3358,7 +3358,7 @@ public void getFeatureVariableDoubleWithListenerUserInExperimentFeatureOn() thro
         testDecisionInfoMap.put(VARIABLE_KEY, validVariableKey);
         testDecisionInfoMap.put(VARIABLE_TYPE, FeatureVariable.VariableType.DOUBLE);
         testDecisionInfoMap.put(VARIABLE_VALUE, 3.14);
-        testDecisionInfoMap.put(SOURCE, FeatureDecision.DecisionSource.FEATURE_TEST);
+        testDecisionInfoMap.put(SOURCE, FeatureDecision.DecisionSource.FEATURE_TEST.toString());
         testDecisionInfoMap.put(SOURCE_INFO, testSourceInfo);
 
         int notificationId = optimizely.notificationCenter.addDecisionNotificationListener(