diff --git a/encoding.go b/encoding.go
index dbe57ee..4be2e38 100644
--- a/encoding.go
+++ b/encoding.go
@@ -174,3 +174,8 @@ func (c ContentType) String() string {
 func (e Encoding) String() string {
 	return string(e)
 }
+
+// String is a standard method to convert an MIMEType into a printable format
+func (e MIMEType) String() string {
+	return string(e)
+}
diff --git a/encoding_test.go b/encoding_test.go
index 11bf991..4c7778a 100644
--- a/encoding_test.go
+++ b/encoding_test.go
@@ -126,3 +126,24 @@ func TestCharset_String(t *testing.T) {
 		})
 	}
 }
+
+// TestContentType_String tests the mime type method of the MIMEType object
+func TestMimeType_String(t *testing.T) {
+	tests := []struct {
+		mt   MIMEType
+		want string
+	}{
+		{MIMEAlternative, "alternative"},
+		{MIMEMixed, "mixed"},
+		{MIMERelated, "related"},
+		{MIMESMime, `signed; protocol="application/pkcs7-signature"; micalg=sha-256`},
+	}
+	for _, tt := range tests {
+		t.Run(tt.mt.String(), func(t *testing.T) {
+			if tt.mt.String() != tt.want {
+				t.Errorf("wrong string for mime type returned. Expected: %s, got: %s",
+					tt.want, tt.mt.String())
+			}
+		})
+	}
+}
diff --git a/util_test.go b/util_test.go
index 47bac43..7c54b7d 100644
--- a/util_test.go
+++ b/util_test.go
@@ -10,6 +10,7 @@ const (
 	keyFilePath  = "dummy-child-key.pem"
 )
 
+// getDummyCertificate loads a certificate and a private key form local disk for testing purposes
 func getDummyCertificate() (*tls.Certificate, error) {
 	keyPair, err := tls.LoadX509KeyPair(certFilePath, keyFilePath)
 	if err != nil {