diff --git a/.gitmodules b/.gitmodules
index 06c9e18..93de146 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,4 +1,4 @@
 [submodule "tests/engine/engine-tests/engine-test-data"]
 	path = tests/engine/engine-tests/engine-test-data
 	url = git@github.com:Flagsmith/engine-test-data.git
-	branch = v3.0.0
+	branch = v3.1.0
diff --git a/flagsmith-engine/evaluation/evaluationContext/mappers.ts b/flagsmith-engine/evaluation/evaluationContext/mappers.ts
index 1fa898f..4593f60 100644
--- a/flagsmith-engine/evaluation/evaluationContext/mappers.ts
+++ b/flagsmith-engine/evaluation/evaluationContext/mappers.ts
@@ -116,11 +116,16 @@ function mapIdentityModelToIdentityContext(
         traitsContext[trait.traitKey] = trait.traitValue;
     }
 
-    return {
+    const identityContext: IdentityContext = {
         identifier: identity.identifier,
-        key: identity.djangoID?.toString() || identity.compositeKey,
         traits: traitsContext
     };
+
+    if (identity.djangoID !== undefined) {
+        identityContext.key = identity.djangoID.toString();
+    }
+
+    return identityContext;
 }
 
 function mapSegmentRuleModelToRule(rule: any): any {
diff --git a/flagsmith-engine/index.ts b/flagsmith-engine/index.ts
index 58f9adc..c57abd0 100644
--- a/flagsmith-engine/index.ts
+++ b/flagsmith-engine/index.ts
@@ -6,7 +6,7 @@ import {
     CustomFeatureMetadata,
     FlagResultWithMetadata
 } from './evaluation/models.js';
-import { getIdentitySegments } from './segments/evaluators.js';
+import { getIdentitySegments, getIdentityKey } from './segments/evaluators.js';
 import { EvaluationResultFlags } from './evaluation/models.js';
 import { TARGETING_REASONS } from './features/types.js';
 import { getHashedPercentageForObjIds } from './utils/hashing/index.js';
@@ -131,7 +131,7 @@ export function evaluateFeatures(
 
         const { value: evaluatedValue, reason: evaluatedReason } = hasOverride
             ? { value: finalFeature.value, reason: undefined }
-            : evaluateFeatureValue(finalFeature, context.identity?.key);
+            : evaluateFeatureValue(finalFeature, getIdentityKey(context));
 
         flags[finalFeature.name] = {
             name: finalFeature.name,
diff --git a/flagsmith-engine/segments/evaluators.ts b/flagsmith-engine/segments/evaluators.ts
index 0b08526..aecae7f 100644
--- a/flagsmith-engine/segments/evaluators.ts
+++ b/flagsmith-engine/segments/evaluators.ts
@@ -49,7 +49,7 @@ export function traitsMatchSegmentCondition(
 ): boolean {
     if (condition.operator === PERCENTAGE_SPLIT) {
         const contextValueKey =
-            getContextValue(condition.property, context) || context?.identity?.key;
+            getContextValue(condition.property, context) || getIdentityKey(context);
         const hashedPercentage = getHashedPercentageForObjIds([segmentKey, contextValueKey]);
         return hashedPercentage <= parseFloat(String(condition.value));
     }
@@ -173,3 +173,9 @@ export function getContextValue(jsonPath: string, context?: GenericEvaluationCon
         return undefined;
     }
 }
+
+export function getIdentityKey(context?: GenericEvaluationContext): string | undefined {
+    if (!context?.identity) return undefined;
+
+    return context.identity.key || `${context.environment.key}_${context.identity.identifier}`;
+}
diff --git a/tests/engine/engine-tests/engine-test-data b/tests/engine/engine-tests/engine-test-data
index 8d19e96..6ab57ec 160000
--- a/tests/engine/engine-tests/engine-test-data
+++ b/tests/engine/engine-tests/engine-test-data
@@ -1 +1 @@
-Subproject commit 8d19e9627013c0e0213c29f3318fd45a179868fa
+Subproject commit 6ab57ec67bc84659e8b5aa41534b04fe45cc4cbe