diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5e273fcb..0ec2a488 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,4 +1,4 @@
-on: [push]
+on: [push, pull_request]
 
 name: Continuous integration
 
diff --git a/src/utils/html.rs b/src/utils/html.rs
index 1011a9c4..a4f5a7d9 100644
--- a/src/utils/html.rs
+++ b/src/utils/html.rs
@@ -128,7 +128,7 @@ mod tests {
     #[test]
     fn test_user_mention() {
         assert_eq!(
-            user_mention(123456789, "<pwner666>"),
+            user_mention(123_456_789, "<pwner666>"),
             "<a href=\"tg://user?id=123456789\">&lt;pwner666&gt;</a>",
         );
     }
diff --git a/src/utils/markdown.rs b/src/utils/markdown.rs
index faf99f7f..329d72ae 100644
--- a/src/utils/markdown.rs
+++ b/src/utils/markdown.rs
@@ -35,7 +35,7 @@ pub fn underline(s: &str) -> String {
     // underline entity, so instead of ___italic underline___ we should use
     // ___italic underline_\r__, where \r is a character with code 13, which
     // will be ignored.
-    if s.starts_with("_") && s.ends_with("_") {
+    if s.starts_with('_') && s.ends_with('_') {
         format!(r"__{}\r__", s)
     } else {
         format!("__{}__", s)
@@ -168,7 +168,7 @@ mod tests {
     #[test]
     fn test_user_mention() {
         assert_eq!(
-            user_mention(123456789, "pwner666"),
+            user_mention(123_456_789, "pwner666"),
             "[pwner666](tg://user?id=123456789)"
         );
     }