diff --git a/src/main/groovy/net/nemerosa/versioning/support/TagSupport.groovy b/src/main/groovy/net/nemerosa/versioning/support/TagSupport.groovy
index 8522418..ec0af64 100644
--- a/src/main/groovy/net/nemerosa/versioning/support/TagSupport.groovy
+++ b/src/main/groovy/net/nemerosa/versioning/support/TagSupport.groovy
@@ -4,14 +4,14 @@ import java.util.regex.Matcher
 
 class TagSupport {
 
-    static int tagOrder(String tagPattern, String tagName) {
+    static BigInteger tagOrder(String tagPattern, String tagName) {
         Matcher m = tagName =~ tagPattern
         if (m.find()) {
             int ngroups = m.groupCount()
             if (ngroups < 1) {
                 throw new IllegalArgumentException("Tag pattern is expected to have at least one number grouping instruction: $tagPattern")
             } else {
-                return m.group(1) as int
+                return new BigInteger(m.group(1))
             }
         } else {
             throw new IllegalStateException("Tag $tagName should have matched $tagPattern")