diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index 63cd14e3..df81b98c 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -36,6 +36,16 @@ android {
     }
 
     signingConfigs {
+        getByName("debug") {
+            // Stable debug keystore committed to the repo so debug APKs keep
+            // the same signature across machines and CI runs. CI runners use
+            // an ephemeral default debug keystore otherwise, which makes every
+            // CI debug APK uninstallable over a previously installed build.
+            storeFile = file("debug.keystore")
+            storePassword = "android"
+            keyAlias = "androiddebugkey"
+            keyPassword = "android"
+        }
         create("release") {
             val isReleaseBuild =
                 gradle.startParameter.taskNames.any { name ->
@@ -301,4 +311,4 @@ tasks.named("check") {
 
 tasks.withType<Test> {
     useJUnitPlatform()
-}
\ No newline at end of file
+}
diff --git a/app/debug.keystore b/app/debug.keystore
new file mode 100644
index 00000000..882c29b6
Binary files /dev/null and b/app/debug.keystore differ