diff --git a/mobile/src/session/mobile-file-syntax.test.ts b/mobile/src/session/mobile-file-syntax.test.ts
index 296fb2c55cc..8f5b31f3252 100644
--- a/mobile/src/session/mobile-file-syntax.test.ts
+++ b/mobile/src/session/mobile-file-syntax.test.ts
@@ -9,6 +9,43 @@ import {
 import type { MobileDiffLine } from './mobile-diff-lines'
 
 describe('mobile file syntax highlighting', () => {
+  it.each(['justfile', 'Justfile', '.justfile', 'tasks.just', 'C:\\repo\\TASKS.JUST'])(
+    'highlights shell recipes in %s',
+    (filePath) => {
+      const source = '# Build recipe\nbuild:\n  echo "ready"\n'
+      const result = highlightMobileCode(source, resolveMobileSyntaxLanguage(filePath))
+      expect(result.highlighted).toBe(true)
+      expect(result.segments.map((segment) => segment.text).join('')).toBe(source)
+      expect(result.segments).toEqual(
+        expect.arrayContaining([
+          { text: '# Build recipe', kind: 'comment' },
+          { text: '"ready"', kind: 'string' }
+        ])
+      )
+    }
+  )
+
+  it.each(['terraform.tfvars', 'C:\\repo\\PROD.TFVARS', 'main.tf', 'config.hcl'])(
+    'highlights HCL assignments in %s',
+    (filePath) => {
+      const source = '# Deployment\nregion = "us-west-2"\ncount = 3\n'
+      const language = resolveMobileSyntaxLanguage(filePath)
+      const result = highlightMobileCode(source, language)
+      expect(result.highlighted).toBe(true)
+      expect(result.segments.map((segment) => segment.text).join('')).toBe(source)
+      expect(result.segments).toEqual(
+        expect.arrayContaining([
+          { text: '# Deployment', kind: 'comment' },
+          { text: 'region', kind: 'variable' },
+          { text: '"us-west-2"', kind: 'string' }
+        ])
+      )
+      const [line] = highlightMobileDiffLines([{ text: 'region = "us-west-2"' }], language)
+      expect(line?.highlighted).toBe(true)
+      expect(line?.segments).toContainEqual({ text: '"us-west-2"', kind: 'string' })
+    }
+  )
+
   it.each([
     ['.env', 'dotenv'],
     ['.env.local', 'dotenv'],
diff --git a/mobile/src/session/mobile-file-syntax.ts b/mobile/src/session/mobile-file-syntax.ts
index ac8df01a02b..3bc9bc7a35a 100644
--- a/mobile/src/session/mobile-file-syntax.ts
+++ b/mobile/src/session/mobile-file-syntax.ts
@@ -55,7 +55,9 @@ const LANGUAGE_ALIASES = new Map([
   ['glimmer-js', 'javascript'],
   ['glimmer-ts', 'typescript'],
   // lowlight has no dotenv grammar; ini covers KEY=value and # comments.
-  ['dotenv', 'ini']
+  ['dotenv', 'ini'],
+  // HCL assignments, strings and comments use the bundled ini grammar on mobile.
+  ['hcl', 'ini']
 ])
 
 export function resolveMobileSyntaxLanguage(filePath: string, preferredLanguage?: string): string {
diff --git a/src/shared/editor-language/editor-language-detect.ts b/src/shared/editor-language/editor-language-detect.ts
index 77c21d7852a..a6adacf30ff 100644
--- a/src/shared/editor-language/editor-language-detect.ts
+++ b/src/shared/editor-language/editor-language-detect.ts
@@ -73,6 +73,7 @@ const EXT_TO_LANGUAGE: Record<string, string> = {
   '.php': 'php',
   '.swift': 'swift',
   '.sh': 'shell',
+  '.just': 'shell',
   '.bash': 'shell',
   '.zsh': 'shell',
   '.fish': 'shell',
@@ -135,6 +136,8 @@ const FILENAME_TO_LANGUAGE: Record<string, string> = {
   Dockerfile: 'dockerfile',
   Jenkinsfile: 'groovy',
   Makefile: 'makefile',
+  Justfile: 'shell',
+  '.justfile': 'shell',
   'CMakeLists.txt': 'cmake',
   '.gitignore': 'ini',
   '.gitattributes': 'ini',