diff --git a/.changeset/tiny-wolves-ignore-tmp.md b/.changeset/tiny-wolves-ignore-tmp.md
new file mode 100644
index 00000000000..62800874539
--- /dev/null
+++ b/.changeset/tiny-wolves-ignore-tmp.md
@@ -0,0 +1,5 @@
+---
+'@shopify/theme': patch
+---
+
+Ignore atomic-write temporary files (e.g. `blocks/foo.liquid.tmp.93809.4dbd82e0b95a`) in the theme dev watcher to prevent crashes when editors save files.
diff --git a/packages/theme/src/cli/constants.ts b/packages/theme/src/cli/constants.ts
index b8a86bd926b..2ac503b0a9c 100644
--- a/packages/theme/src/cli/constants.ts
+++ b/packages/theme/src/cli/constants.ts
@@ -31,6 +31,10 @@ export const DEFAULT_IGNORE_PATTERNS = [
   '**/config.yml',
   '**/node_modules/',
   '.prettierrc.json',
+  // Atomic-write temp files (e.g. blocks/foo.liquid.tmp.bar.baz)
+  '**/{blocks,layout,snippets}/**/*.liquid.tmp.*',
+  '**/{config,locales}/**/*.json.tmp.*',
+  '**/{sections,templates}/**/*.{liquid,json}.tmp.*',
 ]
 
 export const MAX_GRAPHQL_THEME_FILES = 50