diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index da6c621..12bbcfe 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -43,11 +43,31 @@ android {
     // Read from a properties file outside the repository, so the keystore and
     // its password are never in git and a checkout without them still builds
     // (unsigned, which is exactly what an unsigned build should be).
+    // 🔴 **This app's OWN key, not the one every Flamenet Android app shares.**
+    // `.flamenet-android-signing.properties` was made for Flamenet Files, and
+    // because the path is app-agnostic this app silently inherited it — every
+    // release before 2026-08-25 went out as `CN=Flamenet Files`. Nobody chose
+    // that for a messenger; it fell out of the layout.
+    //
+    // It matters because **an Android signing key is permanent**: once a device
+    // installs a build signed with one key, it REFUSES every later build signed
+    // with another. Sharing one key across products also means one compromised
+    // keystore takes out both.
+    //
+    // So: prefer this app's own file, fall back to the shared one so a machine
+    // that only has the old setup still produces a signed build rather than
+    // failing confusingly.
+    //
+    // ⚠️ Both files live outside the repo and hold a password in the clear. They
+    // are never in git, and a checkout without them still builds — unsigned,
+    // which is exactly what an unsigned build should be.
     val signingProperties = Properties()
-    val signingFile = File(System.getProperty("user.home"), ".flamenet-android-signing.properties")
-    if (signingFile.exists()) {
-        signingFile.inputStream().use { signingProperties.load(it) }
-    }
+    val home = File(System.getProperty("user.home"))
+    val signingFile = listOf(
+        File(home, ".flamenet-messenger-signing.properties"),
+        File(home, ".flamenet-android-signing.properties"),
+    ).firstOrNull { it.exists() }
+    signingFile?.inputStream()?.use { signingProperties.load(it) }
 
     signingConfigs {
         if (signingProperties.isNotEmpty()) {