diff --git a/src/index.mjs b/src/index.mjs
index bec70c6..1b78af5 100644
--- a/src/index.mjs
+++ b/src/index.mjs
@@ -31,11 +31,16 @@ async function ghActionBot() {
   const comments = (await getComments(repo, {
     body: new RegExp(COMMENT_BODY_REGEXP, COMMENT_BODY_REGEXP_FLAGS),
     actor: COMMENT_ACTOR,
-  })).filter(comment => !history.get(comment.id));
+  })).filter(comment => !history.get(comment.id)); // skip comments already processed
+
+  if (comments.length) logger.debug(`Found ${comments.length} comments to process`);
 
   // read pull data
   const pulls = (await Promise.all(
     comments.map(async comment => {
+      // keep track of comments that have been processed
+      history.add(comment);
+
       const pull = await getPull(repo, comment.number);
 
       if (pull.state !== 'open') {