diff --git a/Cargo.toml b/Cargo.toml
index 5477e5c..40dcfdf 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -17,3 +17,4 @@ serde_json = "1.0"
 [dev-dependencies]
 assert2 = "0.3"
 pretty_assertions = "1.4"
+rstest = "0.22"
diff --git a/src/patterns/mod.rs b/src/patterns/mod.rs
index 0fa64ad..592a9bd 100644
--- a/src/patterns/mod.rs
+++ b/src/patterns/mod.rs
@@ -12,5 +12,5 @@ pub fn marker_pattern() -> Result<Regex> {
 
 /// The pattern to find an issue number on an already found TODO or FIXME comment
 pub fn issue_pattern() -> Result<Regex> {
-    regex::Regex::new(r"( |)(\(|\(#)(?P<ISSUE_NUMBER>\d+)(\))").context("issue regex")
+    regex::Regex::new(r"\(#?(?P<ISSUE_NUMBER>\d+)\)").context("issue regex")
 }
diff --git a/src/patterns/tests/issue.rs b/src/patterns/tests/issue.rs
index f0845a1..869fe16 100644
--- a/src/patterns/tests/issue.rs
+++ b/src/patterns/tests/issue.rs
@@ -1,8 +1,10 @@
+use anyhow::Result;
+
 //
 use super::*;
 
 #[test]
-fn when_issue_should_find_number() -> anyhow::Result<()> {
+fn when_issue_should_find_number() -> Result<()> {
     //given
     let line = " a line with a // TODO: (#13) issue number";
 
@@ -18,8 +20,24 @@ fn when_issue_should_find_number() -> anyhow::Result<()> {
     Ok(())
 }
 
+#[rstest::rstest]
+#[case("(#13)")]
+#[case("(13)")]
+fn find_issue_thirteen(#[case] input: &str) -> Result<()> {
+    assert_eq!(
+        issue_pattern()?
+            .captures(input)
+            .unwrap()
+            .name("ISSUE_NUMBER")
+            .unwrap()
+            .as_str(),
+        "13"
+    );
+    Ok(())
+}
+
 #[test]
-fn when_no_issue_should_find_nothing() -> anyhow::Result<()> {
+fn when_no_issue_should_find_nothing() -> Result<()> {
     //given
     let line = " a line with a // TODO: and no issue number";