diff --git a/js/components/MatchModal.js b/js/components/MatchModal.js
index e2eef0c..9a84a30 100644
--- a/js/components/MatchModal.js
+++ b/js/components/MatchModal.js
@@ -10,7 +10,11 @@ export function MatchModal(props) {
     switch (props.match.state) {
     case 'in_progress':
         title = 'Spiel läuft';
-        actionButton = <Button color='primary' onClick={props.endMatch}>Spiel beenden</Button>;
+        if (!props.match.allowUndecided && props.match.team1.score === props.match.team2.score) {
+            actionButton = <Button color='primary' disabled>Spiel beenden</Button>;
+        } else {
+            actionButton = <Button color='primary' onClick={props.endMatch}>Spiel beenden</Button>;
+        }
         break;
     case 'finished':
         title = 'Spiel beendet';
diff --git a/pages/tournament.js b/pages/tournament.js
index a7bc42e..575e47f 100644
--- a/pages/tournament.js
+++ b/pages/tournament.js
@@ -94,7 +94,7 @@ function convertTournament(apiTournament) {
         } else {
             // playoff stage
             playoffStages.push({
-                id: stage.id, level: stage.level, matches: stage.matches.map(match => convertMatch(match))
+                id: stage.id, level: stage.level, matches: stage.matches.map(match => convertMatch(match, false))
             });
         }
     }
@@ -115,13 +115,14 @@ function convertGroup(apiGroup) {
         id: apiGroup.id,
         number: apiGroup.number,
         scores: apiGroup.group_scores,
-        matches: apiGroup.matches.map(match => convertMatch(match))
+        matches: apiGroup.matches.map(match => convertMatch(match, true))
     };
 }
 
-function convertMatch(apiMatch) {
+function convertMatch(apiMatch, allowUndecided) {
     const result = {
-        id: apiMatch.id, state: apiMatch.state, winnerTeamId: apiMatch.winner === null ? null : apiMatch.winner.id
+        id: apiMatch.id, state: apiMatch.state, allowUndecided: allowUndecided,
+        winnerTeamId: apiMatch.winner === null ? null : apiMatch.winner.id
     };
 
     if (apiMatch.match_scores.length === 2) {