diff --git a/src/TodoByVersionRule.php b/src/TodoByVersionRule.php
index 8d27200..0fb8c82 100644
--- a/src/TodoByVersionRule.php
+++ b/src/TodoByVersionRule.php
@@ -30,7 +30,7 @@ final class TodoByVersionRule implements Rule
             @?[a-zA-Z0-9_-]*\s* # optional username
             \s*[:-]?\s* # optional colon or hyphen
             \s+ # keyword/version separator
-            (?P<version>[<>=]?[^\s:\-]+) # version
+            (?P<version>[<>=]?[0-9]+[^\s:\-]+) # version
             \s*[:-]?\s* # optional colon or hyphen
             (?P<comment>.*) # rest of line as comment text
         }ix
diff --git a/tests/data/version.php b/tests/data/version.php
index b9a0ff5..f237479 100644
--- a/tests/data/version.php
+++ b/tests/data/version.php
@@ -10,3 +10,8 @@ function doFoo():void {
 // TODO: <1.0.0
 // TODO: <1.0
 // TODO: 1.0
+
+// should not error in TodoByVersionRule
+// TODO php:8.0.0
+// TODO php:8.0
+// TODO php:8