diff --git a/plugins/splunk-on-call/src/components/TriggerDialog/TriggerDialog.tsx b/plugins/splunk-on-call/src/components/TriggerDialog/TriggerDialog.tsx
index 425f25cc25..dd8f0b1909 100644
--- a/plugins/splunk-on-call/src/components/TriggerDialog/TriggerDialog.tsx
+++ b/plugins/splunk-on-call/src/components/TriggerDialog/TriggerDialog.tsx
@@ -59,7 +59,7 @@ const useStyles = makeStyles((theme: Theme) =>
       display: 'flex',
       flexDirection: 'row',
       alignItems: 'center',
-      minWidth: `calc(100% - ${theme.spacing(2)})`,
+      minWidth: `calc(100% - ${theme.spacing(2)}px)`,
     },
     formHeader: {
       width: '50%',