diff --git a/src/backport.ts b/src/backport.ts
index 5f047ec..feaa10b 100644
--- a/src/backport.ts
+++ b/src/backport.ts
@@ -105,15 +105,6 @@ export class Backport {
 
       if (repo === undefined) throw new Error("No repository defined!");
 
-      if (
-        this.config.source_pr_number !== undefined &&
-        this.github.getEventName() !== "workflow_dispatch"
-      ) {
-        throw new Error(
-          "source_pr_number can only be specified for workflow_dispatch events!",
-        );
-      }
-
       const pull_number =
         this.config.source_pr_number === undefined
           ? this.github.getPullNumber()