diff --git a/README.md b/README.md
index f9cb3b4..8ddb151 100644
--- a/README.md
+++ b/README.md
@@ -77,6 +77,10 @@ Appen er designet etter «offline-first»-prinsippet:
 - Databaseoppdateringer er atomiske (transaksjon) for å unngå datatap
 - Ingen persondata lagres — kun tilfluktsromdata og kartfliser
 
+## Opphavsrett
+
+Copyright (c) Ole-Morten Duesund <olemd@glemt.net>
+
 ## Lisens
 
 Kildekoden er lisensiert under [Mozilla Public License 2.0](LICENSE).
diff --git a/app/src/main/res/layout/dialog_civil_defense.xml b/app/src/main/res/layout/dialog_civil_defense.xml
index b598f75..29333d4 100644
--- a/app/src/main/res/layout/dialog_civil_defense.xml
+++ b/app/src/main/res/layout/dialog_civil_defense.xml
@@ -114,5 +114,14 @@
             android:textSize="12sp"
             android:textStyle="italic" />
 
+        <!-- Copyright notice -->
+        <TextView
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="16dp"
+            android:text="@string/app_copyright"
+            android:textColor="@color/text_secondary"
+            android:textSize="11sp" />
+
     </LinearLayout>
 </ScrollView>
diff --git a/app/src/main/res/values-nb/strings.xml b/app/src/main/res/values-nb/strings.xml
index 7a815cd..ef3f555 100644
--- a/app/src/main/res/values-nb/strings.xml
+++ b/app/src/main/res/values-nb/strings.xml
@@ -82,4 +82,7 @@
     <string name="civil_defense_step5_title">5. Faren over</string>
     <string name="civil_defense_step5_body">Én sammenhengende tone på omtrent 30 sekunder. Faren eller angrepet er over. Fortsett å følge instruksjoner fra myndighetene.</string>
     <string name="civil_defense_source">Kilde: DSB (Direktoratet for samfunnssikkerhet og beredskap)</string>
+
+    <!-- Opphavsrett -->
+    <string name="app_copyright">Opphavsrett © Ole-Morten Duesund</string>
 </resources>
diff --git a/app/src/main/res/values-nn/strings.xml b/app/src/main/res/values-nn/strings.xml
index 0629cb6..33231c1 100644
--- a/app/src/main/res/values-nn/strings.xml
+++ b/app/src/main/res/values-nn/strings.xml
@@ -82,4 +82,7 @@
     <string name="civil_defense_step5_title">5. Faren over</string>
     <string name="civil_defense_step5_body">Éin samanhengande tone på omtrent 30 sekund. Faren eller åtaket er over. Hald fram med å følgje instruksjonar frå styresmaktene.</string>
     <string name="civil_defense_source">Kjelde: DSB (Direktoratet for samfunnstryggleik og beredskap)</string>
+
+    <!-- Opphavsrett -->
+    <string name="app_copyright">Opphavsrett © Ole-Morten Duesund</string>
 </resources>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index ede64d0..8da6f26 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -82,4 +82,7 @@
     <string name="civil_defense_step5_title">5. All clear</string>
     <string name="civil_defense_step5_body">One continuous tone lasting approximately 30 seconds. The danger or attack is over. Continue to follow instructions from authorities.</string>
     <string name="civil_defense_source">Source: DSB (Norwegian Directorate for Civil Protection)</string>
+
+    <!-- Copyright -->
+    <string name="app_copyright">Copyright © Ole-Morten Duesund</string>
 </resources>