diff --git a/package.json b/package.json
index b50ae32f1..8a90807d6 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "open-plc-editor",
   "description": "OpenPLC Editor - IDE capable of creating programs for the OpenPLC Runtime",
-  "version": "4.2.9",
+  "version": "4.2.10",
   "license": "GPL-3.0",
   "author": {
     "name": "Autonomy Logic"
diff --git a/src/frontend/data/constants/app-version.ts b/src/frontend/data/constants/app-version.ts
index 661f491e9..3b99e5528 100644
--- a/src/frontend/data/constants/app-version.ts
+++ b/src/frontend/data/constants/app-version.ts
@@ -18,4 +18,4 @@
  * compares a per-deploy `BUILD_ID` (git commit SHA), not this version, so a
  * stale tab is detected on every deploy even without a version bump.
  */
-export const APP_VERSION = '4.2.9'
+export const APP_VERSION = '4.2.10'
diff --git a/src/frontend/store/__tests__/project-validation-variables.test.ts b/src/frontend/store/__tests__/project-validation-variables.test.ts
index 3a058464d..5c1611677 100644
--- a/src/frontend/store/__tests__/project-validation-variables.test.ts
+++ b/src/frontend/store/__tests__/project-validation-variables.test.ts
@@ -507,6 +507,15 @@ describe('updateVariableValidation', () => {
     expect(result.ok).toBe(true)
   })
 
+  it.each(['%QX0.0', '%IX0.0', '%MX0.0', '%MX3.7'])(
+    'accepts every valid IEC area prefix for BOOL locations (%s)',
+    (location) => {
+      const boolVar = makeVariable('Test', 'BOOL', '')
+      const result = updateVariableValidation([], { location }, boolVar)
+      expect(result.ok).toBe(true)
+    },
+  )
+
   it('returns ok: true when location is valid for WORD type', () => {
     const wordVar = makeVariable('Test', 'WORD', '')
     const result = updateVariableValidation([], { location: '%QW0' }, wordVar)
diff --git a/src/frontend/store/slices/project/validation/variables.ts b/src/frontend/store/slices/project/validation/variables.ts
index b8baf4ee2..24a570ac9 100644
--- a/src/frontend/store/slices/project/validation/variables.ts
+++ b/src/frontend/store/slices/project/validation/variables.ts
@@ -153,7 +153,7 @@ const variableLocationValidation = (variableLocation: string, variableType: stri
 const variableLocationValidationErrorMessage = (variableType: string) => {
   switch (variableType.toUpperCase()) {
     case 'BOOL':
-      return 'Valid locations: %QX0.0..7, %IX0.0..7 (change the number to the desired location)'
+      return 'Valid locations: %QX0.0..7, %IX0.0..7, %MX0.0..7 (change the number to the desired location)'
     case 'INT':
     case 'UINT':
     case 'WORD':
diff --git a/src/frontend/utils/PLC/address-constants/types.ts b/src/frontend/utils/PLC/address-constants/types.ts
index 7ef3179a2..5ab477d40 100644
--- a/src/frontend/utils/PLC/address-constants/types.ts
+++ b/src/frontend/utils/PLC/address-constants/types.ts
@@ -1,6 +1,7 @@
 export const PLC_ADDRESS_PREFIX = {
   BOOL_OUTPUT: '%QX',
   BOOL_INPUT: '%IX',
+  BOOL_MEMORY: '%MX',
   WORD_OUTPUT: '%QW',
   WORD_INPUT: '%IW',
   WORD_MEMORY: '%MW',
@@ -12,7 +13,10 @@ export const PLC_ADDRESS_PREFIX = {
   LWORD_MEMORY: '%ML',
 } as const
 
-export const BOOL_LOCATION_REGEX = /^%[QI]X\d+\.\d$/
+// Accept every valid IEC area prefix — input (I), output (Q) and memory (M).
+// `%MX` memory bits are legitimate (e.g. Modbus coils) and were previously
+// rejected here, unlike the word-width regexes below which already allow M.
+export const BOOL_LOCATION_REGEX = /^%[QIM]X\d+\.\d$/
 export const WORD_LOCATION_REGEX = /^%[QIM]W\d+$/
 export const DWORD_LOCATION_REGEX = /^%[QIM]D\d+$/
 export const LWORD_LOCATION_REGEX = /^%[QIM]L\d+$/