diff --git a/plugin/tags.go b/tag/semver.go
similarity index 71%
rename from plugin/tags.go
rename to tag/semver.go
index 157a2cb..9101b83 100644
--- a/plugin/tags.go
+++ b/tag/semver.go
@@ -1,4 +1,4 @@
-package plugin
+package tag
 
 import (
 	"fmt"
@@ -72,29 +72,3 @@ func SemverTags(ref string, strict bool) ([]string, error) {
 		fmt.Sprintf("%v.%v.%v", version.Major(), version.Minor(), version.Patch()),
 	}, nil
 }
-
-// IsTaggable checks whether tags should be created for the specified ref.
-// The function returns true if the ref either matches the default branch
-// or is a tag ref.
-func IsTaggable(ref, defaultBranch string) bool {
-	if strings.HasPrefix(ref, "refs/tags/") {
-		return true
-	}
-
-	if stripHeadPrefix(ref) == defaultBranch {
-		return true
-	}
-
-	return false
-}
-
-func stripHeadPrefix(ref string) string {
-	return strings.TrimPrefix(ref, "refs/heads/")
-}
-
-func stripTagPrefix(ref string) string {
-	ref = strings.TrimPrefix(ref, "refs/tags/")
-	ref = strings.TrimPrefix(ref, "v")
-
-	return ref
-}
diff --git a/plugin/tags_test.go b/tag/semver_test.go
similarity index 99%
rename from plugin/tags_test.go
rename to tag/semver_test.go
index 299e424..7833faf 100644
--- a/plugin/tags_test.go
+++ b/tag/semver_test.go
@@ -1,4 +1,4 @@
-package plugin
+package tag
 
 import (
 	"reflect"
diff --git a/tag/util.go b/tag/util.go
new file mode 100644
index 0000000..83ef05b
--- /dev/null
+++ b/tag/util.go
@@ -0,0 +1,29 @@
+package tag
+
+import "strings"
+
+func stripHeadPrefix(ref string) string {
+	return strings.TrimPrefix(ref, "refs/heads/")
+}
+
+func stripTagPrefix(ref string) string {
+	ref = strings.TrimPrefix(ref, "refs/tags/")
+	ref = strings.TrimPrefix(ref, "v")
+
+	return ref
+}
+
+// IsTaggable checks whether tags should be created for the specified ref.
+// The function returns true if the ref either matches the default branch
+// or is a tag ref.
+func IsTaggable(ref, defaultBranch string) bool {
+	if strings.HasPrefix(ref, "refs/tags/") {
+		return true
+	}
+
+	if stripHeadPrefix(ref) == defaultBranch {
+		return true
+	}
+
+	return false
+}