diff --git a/frontend/src/components/forms/common_custom_times_matches.tsx b/frontend/src/components/forms/common_custom_times_matches.tsx
index 31396cdae..ab61be8d6 100644
--- a/frontend/src/components/forms/common_custom_times_matches.tsx
+++ b/frontend/src/components/forms/common_custom_times_matches.tsx
@@ -64,7 +64,7 @@ export default function CommonCustomTimeMatchesForm<
       <Grid align="center">
         <Grid.Col span={{ sm: 8 }}>
           <NumberInput
-            label={t('custom_match_margin_label')}
+            label={t('custom_match_duration_label')}
             disabled={!customDurationEnabled}
             rightSection={<Text>{t('minutes')}</Text>}
             placeholder={`${match.duration_minutes}`}
@@ -112,12 +112,6 @@ export default function CommonCustomTimeMatchesForm<
       </Grid>
 
       <Input.Wrapper label={t('next_match_time_label')} mt="sm">
-        {/* <Input component={BareDateTime}
-            datetime={fromUnixTime(
-              getUnixTime(parseISO(match.start_time)) + matchDuration * 60 + matchMargin * 60
-            )}
-            formatStr="d LLLL yyyy HH:mm"
-          /> */}
         <Input
           component="time"
           dateTime={endDatetime.toISOString()}
diff --git a/frontend/src/components/modals/match_modal.tsx b/frontend/src/components/modals/match_modal.tsx
index 089a2240c..a30a986c9 100644
--- a/frontend/src/components/modals/match_modal.tsx
+++ b/frontend/src/components/modals/match_modal.tsx
@@ -132,7 +132,13 @@ export default function MatchModal({
           />
           <Divider mt="lg" />
 
-          <CommonCustomTimeMatchesForm customDurationEnabled={customDurationEnabled} customMarginEnabled={customMarginEnabled} form={form} match={match} setCustomDurationEnabled={setCustomDurationEnabled} setCustomMarginEnabled={setCustomMarginEnabled} />
+          <CommonCustomTimeMatchesForm customDurationEnabled={customDurationEnabled} customMarginEnabled={customMarginEnabled} form={form} match={match} setCustomDurationEnabled={(val) => {
+            setCustomDurationEnabled(val);
+            if (val === false) form.setFieldValue('custom_duration_minutes', null);
+          }} setCustomMarginEnabled={(val) => {
+            setCustomMarginEnabled(val);
+            if (val === false) form.setFieldValue('custom_margin_minutes', null);
+          }} />
 
           <Button fullWidth style={{ marginTop: 20 }} color="green" type="submit">
             {t('save_button')}
diff --git a/frontend/src/components/modals/match_update_modal.tsx b/frontend/src/components/modals/match_update_modal.tsx
index fb3503380..b29196ac2 100644
--- a/frontend/src/components/modals/match_update_modal.tsx
+++ b/frontend/src/components/modals/match_update_modal.tsx
@@ -106,12 +106,13 @@ export default function MatchUpdateModal({
                     disabled={date === null}
                     onClick={async () => {
                       const computedMargin = Math.floor(
-                        (date!.getTime() +
-                          (previousMatch.custom_duration_minutes ??
-                            previousMatch.duration_minutes) *
+                        (date!.getTime() -
+                          parseISO(previousMatch.start_time).getTime() +
+                          (previousMatch.custom_duration_minutes === null
+                            ? previousMatch.duration_minutes
+                            : previousMatch.custom_duration_minutes) *
                             60 *
-                            1000 -
-                          parseISO(previousMatch.start_time).getTime()) /
+                            1000) /
                           60 /
                           1000
                       );