diff --git a/lib/workers/branch/schedule.ts b/lib/workers/branch/schedule.ts
index c3ff3f3636ed475ae45d51bf2c9899ad47afe1fc..c46d3b794f50ebe43d09ba7296bcd81a4b14e751 100644
--- a/lib/workers/branch/schedule.ts
+++ b/lib/workers/branch/schedule.ts
@@ -16,7 +16,7 @@ export function hasValidTimezone(
   timezone: string
 ): [boolean] | [boolean, string] {
   if (!moment.tz.zone(timezone)) {
-    return [false, `Invalid timezone: ${timezone}`];
+    return [false, `Invalid schedule: Unsupported timezone ${timezone}`];
   }
   return [true];
 }
@@ -39,12 +39,12 @@ export function hasValidSchedule(
     );
     const parsedSchedule = later.parse.text(massagedText);
     if (parsedSchedule.error !== -1) {
-      message = `Failed to parse schedule "${scheduleText}"`;
+      message = `Invalid schedule: Failed to parse "${scheduleText}"`;
       // It failed to parse
       return true;
     }
     if (parsedSchedule.schedules.some(s => s.m)) {
-      message = `Schedule "${scheduleText}" should not specify minutes`;
+      message = `Invalid schedule: "${scheduleText}" should not specify minutes`;
       return true;
     }
     if (
@@ -52,7 +52,7 @@ export function hasValidSchedule(
         s => s.M || s.d !== undefined || s.D || s.t_a !== undefined || s.t_b
       )
     ) {
-      message = `Schedule "${scheduleText}" has no months, days of week or time of day`;
+      message = `Invalid schedule: "${scheduleText}" has no months, days of week or time of day`;
       return true;
     }
     // It must be OK
diff --git a/test/config/__snapshots__/validation.spec.ts.snap b/test/config/__snapshots__/validation.spec.ts.snap
index 05e4eb1e594d6c4f7aec7a72e9bc7c05b533e173..1cefb6bf69df24f6e69254e243fd1833347507ca 100644
--- a/test/config/__snapshots__/validation.spec.ts.snap
+++ b/test/config/__snapshots__/validation.spec.ts.snap
@@ -41,11 +41,11 @@ Array [
   },
   Object {
     "depName": "Configuration Error",
-    "message": "Invalid schedule: \`Schedule \\"every 15 mins every weekday\\" should not specify minutes\`",
+    "message": "Invalid schedule: \`Invalid schedule: \\"every 15 mins every weekday\\" should not specify minutes\`",
   },
   Object {
     "depName": "Configuration Error",
-    "message": "extends: Invalid timezone: Europe/Brussel",
+    "message": "extends: Invalid schedule: Unsupported timezone Europe/Brussel",
   },
   Object {
     "depName": "Configuration Error",
@@ -57,7 +57,7 @@ Array [
   },
   Object {
     "depName": "Configuration Error",
-    "message": "timezone: Invalid timezone: Asia",
+    "message": "timezone: Invalid schedule: Unsupported timezone Asia",
   },
 ]
 `;