diff --git a/licenses/classifier.go b/licenses/classifier.go
index 3550990b..90a65417 100644
--- a/licenses/classifier.go
+++ b/licenses/classifier.go
@@ -30,7 +30,7 @@ type googleClassifier struct {
 	classifier *licenseclassifier.Classifier
 }
 
-// NewClassifier creates a classifier
+// NewClassifier creates a classifier.
 func NewClassifier() (Classifier, error) {
 	c, err := assets.DefaultClassifier()
 	if err != nil {
diff --git a/licenses/types.go b/licenses/types.go
index 8b86a1f6..ca679ded 100644
--- a/licenses/types.go
+++ b/licenses/types.go
@@ -3,7 +3,7 @@ package licenses
 // Type identifies a class of software license.
 type Type string
 
-// License types
+// License types.
 const (
 	// Unknown license type.
 	Unknown = Type("")
diff --git a/licenses/types_test.go b/licenses/types_test.go
index 6b443c47..b64ab227 100644
--- a/licenses/types_test.go
+++ b/licenses/types_test.go
@@ -43,3 +43,31 @@ func TestTypes(t *testing.T) {
 		}
 	}
 }
+
+func TestTypeString(t *testing.T) {
+	if got := Unknown.String(); got != "unknown" {
+		t.Errorf("Unknown.String() = %q, want %q", got, "unknown")
+	}
+	if got := Restricted.String(); got != "restricted" {
+		t.Errorf("Restricted.String() = %q, want %q", got, "restricted")
+	}
+	if got := Permissive.String(); got != "permissive" {
+		t.Errorf("Permissive.String() = %q, want %q", got, "permissive")
+	}
+}
+
+func TestLicenseType(t *testing.T) {
+	if got := LicenseType("Apache-2.0"); got != Notice {
+		t.Errorf("LicenseType(Apache-2.0) = %v, want %v", got, Notice)
+	}
+	if got := LicenseType("MIT"); got != Notice {
+		t.Errorf("LicenseType(MIT) = %v, want %v", got, Notice)
+	}
+	if got := LicenseType("GPL-3.0"); got != Restricted {
+		t.Errorf("LicenseType(GPL-3.0) = %v, want %v", got, Restricted)
+	}
+	if got := LicenseType("NonExistentLicense"); got != Unknown {
+		t.Errorf("LicenseType(NonExistentLicense) = %v, want %v", got, Unknown)
+	}
+}
+