diff --git a/CHANGES.txt b/CHANGES.txt
index 17f636b47..5657c17ec 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,3 +1,6 @@
+10.17.3 (XXX XX, 2022)
+ - Updated format for MySegments keys in LocalStorage, keeping backwards compatibility.
+
 10.17.2 (January 31, 2022)
  - Updated some dependencies for vulnerability fixes.
  - Bugfixing - Fixed internal handling of Fetch API promise rejection, to avoid unhandled exceptions on some Web browsers (issue https://github.com/splitio/javascript-client/issues/621)
diff --git a/package-lock.json b/package-lock.json
index b06dda9be..487c28124 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "@splitsoftware/splitio",
-  "version": "10.17.2",
+  "version": "10.17.3-rc.4",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
diff --git a/package.json b/package.json
index 9192a6dc9..3c7272270 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@splitsoftware/splitio",
-  "version": "10.17.2",
+  "version": "10.17.3-rc.4",
   "description": "Split SDK",
   "files": [
     "README.md",
diff --git a/src/storage/KeysLocalStorage.js b/src/storage/KeysLocalStorage.js
index 1c9a044f6..1e59cec66 100644
--- a/src/storage/KeysLocalStorage.js
+++ b/src/storage/KeysLocalStorage.js
@@ -10,11 +10,11 @@ class KeyBuilderForLocalStorage extends KeyBuilder {
   }
 
   buildSegmentNameKey(segmentName) {
-    return `${matching(this.settings.core.key)}.${this.settings.storage.prefix}.segment.${segmentName}`;
+    return `${this.settings.storage.prefix}.${matching(this.settings.core.key)}.segment.${segmentName}`;
   }
 
   extractSegmentName(builtSegmentKeyName) {
-    const prefix = `${matching(this.settings.core.key)}.${this.settings.storage.prefix}.segment.`;
+    const prefix = `${this.settings.storage.prefix}.${matching(this.settings.core.key)}.segment.`;
 
     if (startsWith(builtSegmentKeyName, prefix))
       return builtSegmentKeyName.substr(prefix.length);
@@ -35,6 +35,18 @@ class KeyBuilderForLocalStorage extends KeyBuilder {
   buildSplitsFilterQueryKey() {
     return `${this.settings.storage.prefix}.splits.filterQuery`;
   }
+
+  // @BREAKING: The key used to start with the matching key instead of the prefix, this was changed on version 10.17.3
+  buildOldSegmentNameKey(segmentName) {
+    return `${matching(this.settings.core.key)}.${this.settings.storage.prefix}.segment.${segmentName}`;
+  }
+  // @BREAKING: The key used to start with the matching key instead of the prefix, this was changed on version 10.17.3
+  extractOldSegmentKey(maybeOldKey) {
+    const prefix = `${matching(this.settings.core.key)}.${this.settings.storage.prefix}.segment.`;
+
+    if (startsWith(maybeOldKey, prefix))
+      return maybeOldKey.substr(prefix.length);
+  }
 }
 
 export default KeyBuilderForLocalStorage;
diff --git a/src/storage/SegmentCache/InLocalStorage/index.js b/src/storage/SegmentCache/InLocalStorage/index.js
index 526588dbd..82b2e60b9 100644
--- a/src/storage/SegmentCache/InLocalStorage/index.js
+++ b/src/storage/SegmentCache/InLocalStorage/index.js
@@ -46,9 +46,29 @@ class SegmentCacheInLocalStorage {
 
     // Scan current values from localStorage
     const storedSegmentNames = Object.keys(localStorage).reduce((accum, key) => {
-      const segmentName = this.keys.extractSegmentName(key);
-
-      if (segmentName) accum.push(segmentName);
+      let segmentName = this.keys.extractSegmentName(key);
+
+      if (segmentName) {
+        accum.push(segmentName);
+      } else {
+        // @BREAKING: This is only to clean up "old" keys. Remove this whole else code block.
+        segmentName = this.keys.extractOldSegmentKey(key);
+
+        if (segmentName) { // this was an old segment key, let's clean up.
+          const newSegmentKey = this.keys.buildSegmentNameKey(segmentName);
+          try {
+            // If the new format key is not there, create it.
+            if (!localStorage.getItem(newSegmentKey) && segmentNames.indexOf(segmentName) > -1) {
+              localStorage.setItem(newSegmentKey, DEFINED);
+              // we are migrating a segment, let's track it.
+              accum.push(segmentName);
+            }
+            localStorage.removeItem(key); // we migrated the current key, let's delete it.
+          } catch (e) {
+            log.error(e);
+          }
+        }
+      }
 
       return accum;
     }, []);
@@ -65,7 +85,7 @@ class SegmentCacheInLocalStorage {
       segmentNames.forEach(segmentName => this.addToSegment(segmentName));
     } else {
       // Slowest path => we need to find at least 1 difference because
-      for(index = 0; index < segmentNames.length && storedSegmentNames.indexOf(segmentNames[index]) !== -1; index++) {
+      for (index = 0; index < segmentNames.length && storedSegmentNames.indexOf(segmentNames[index]) !== -1; index++) {
         // TODO: why empty statement?
       }
 
diff --git a/src/storage/__tests__/SegmentCache/InLocalStorage/browser.spec.js b/src/storage/__tests__/SegmentCache/InLocalStorage/browser.spec.js
index 9bb772504..63c61d8bc 100644
--- a/src/storage/__tests__/SegmentCache/InLocalStorage/browser.spec.js
+++ b/src/storage/__tests__/SegmentCache/InLocalStorage/browser.spec.js
@@ -19,5 +19,41 @@ tape('SEGMENT CACHE / in LocalStorage', assert => {
 
   assert.ok( cache.isInSegment('mocked-segment') === false );
 
+  cache.flush();
+  assert.end();
+});
+
+// @BREAKING: REMOVE when removing this backwards compatibility.
+tape('SEGMENT CACHE / in LocalStorage migration for mysegments keys', assert => {
+
+  const keys = new KeyBuilder(SettingsFactory({
+    core: { key: 'test_nico' },
+    storage:{ prefix: 'LS_BC_test'}
+  }));
+  const cache =  new SegmentCacheInLocalStorage(keys);
+  const oldKey1 = 'test_nico.LS_BC_test.SPLITIO.segment.segment1';
+  const oldKey2 = 'test_nico.LS_BC_test.SPLITIO.segment.segment2';
+  const newKey1 = keys.buildSegmentNameKey('segment1');
+  const newKey2 = keys.buildSegmentNameKey('segment2');
+
+  cache.flush(); // cleanup before starting.
+
+  // Not adding a full suite for LS keys now, testing here
+  assert.equal(oldKey1, keys.buildOldSegmentNameKey('segment1'));
+  assert.equal('segment1', keys.extractOldSegmentKey(oldKey1));
+
+  // add two segments, one we don't want to send on reset, should only be cleared, other one will be migrated.
+  localStorage.setItem(oldKey1, 1);
+  localStorage.setItem(oldKey2, 1);
+  assert.equal(localStorage.getItem(newKey1), null, 'control assertion');
+
+  cache.resetSegments(['segment1']);
+
+  assert.equal(localStorage.getItem(newKey1), '1', 'The segment key for segment1, as is part of the new list, should be migrated.');
+  assert.equal(localStorage.getItem(newKey2), null, 'The segment key for segment2 should not be migrated.');
+  assert.equal(localStorage.getItem(oldKey1), null, 'Old keys are removed.');
+  assert.equal(localStorage.getItem(oldKey2), null, 'Old keys are removed.');
+
+  cache.flush();
   assert.end();
 });
\ No newline at end of file
diff --git a/src/utils/settings/index.js b/src/utils/settings/index.js
index ea1507169..b43239cc2 100644
--- a/src/utils/settings/index.js
+++ b/src/utils/settings/index.js
@@ -27,7 +27,7 @@ import { API } from '../../utils/logger';
 import { STANDALONE_MODE, STORAGE_MEMORY, CONSUMER_MODE, OPTIMIZED } from '../../utils/constants';
 import validImpressionsMode from './impressionsMode';
 
-const version = '10.17.2';
+const version = '10.17.3-rc.4';
 const eventsEndpointMatcher = /^\/(testImpressions|metrics|events)/;
 const authEndpointMatcher = /^\/v2\/auth/;
 const streamingEndpointMatcher = /^\/(sse|event-stream)/;