diff --git a/CHANGELOG.md b/CHANGELOG.md
index 98bdf47..dc81524 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   anything Calendula can't represent (changed recurring occurrences, guest
   lists) is reported rather than silently dropped.
 
+### Fixed
+- Fixed the app crashing immediately on every launch in the optimized release
+  build: release code-shrinking (R8) was stripping a database class the
+  home-screen widget framework needs, so the app died at startup before showing
+  anything. Added the missing keep rule.
+
 ## [2.6.0] — 2026-06-18
 
 ### Added
diff --git a/app/proguard-rules.pro b/app/proguard-rules.pro
index dccc1da..dce5b77 100644
--- a/app/proguard-rules.pro
+++ b/app/proguard-rules.pro
@@ -4,3 +4,14 @@
 
 # Compose Compiler may keep its own; defaults are fine
 -dontwarn org.jetbrains.annotations.**
+
+# Room database implementations (pulled in transitively via
+# androidx.glance:glance-appwidget → androidx.work → androidx.room).
+# The widgets rely on Glance, whose WorkManager backend stores state in a Room
+# database. Under R8 full mode (AGP 9 default) the generated *_Impl subclasses
+# of RoomDatabase lose their usable no-arg constructor / are marked abstract,
+# so Room's reflective instantiation throws InstantiationException and the app
+# crashes at startup with "Failed to create an instance of ...WorkDatabase".
+# Keep the generated Room database implementations fully intact.
+-keep class * extends androidx.room.RoomDatabase { *; }
+-dontwarn androidx.room.paging.**