diff --git a/src/claims.js b/src/claims.js
index 5d897c6..5449ba9 100644
--- a/src/claims.js
+++ b/src/claims.js
@@ -61,16 +61,16 @@ const runVerificationJson = (
   if (checkPath.length == 0) {
     switch (checkRelation) {
       default:
-      case 'contains':
+      case E.ClaimRelation.CONTAINS:
         re = new RegExp(checkClaim, 'gi')
         res.isVerified = re.test(proofData.replace(/\r?\n|\r|\\/g, ''))
         break
-      case 'equals':
+      case E.ClaimRelation.EQUALS:
         res.isVerified =
           proofData.replace(/\r?\n|\r|\\/g, '').toLowerCase() ==
           checkClaim.toLowerCase()
         break
-      case 'oneOf':
+      case E.ClaimRelation.ONEOF:
         re = new RegExp(checkClaim, 'gi')
         res.isVerified = re.test(proofData.join('|'))
         break
@@ -102,7 +102,7 @@ const runVerification = (proofData, spData) => {
   }
 
   switch (spData.proof.format) {
-    case 'json':
+    case E.ProofFormat.JSON:
       res = runVerificationJson(
         res,
         proofData,
@@ -111,7 +111,7 @@ const runVerification = (proofData, spData) => {
         spData.claim.relation
       )
       break
-    case 'text':
+    case E.ProofFormat.TEXT:
       re = new RegExp(
         utils
           .generateClaim(spData.claim.fingerprint, spData.claim.format)
diff --git a/src/utils.js b/src/utils.js
index 9283227..9e656cb 100644
--- a/src/utils.js
+++ b/src/utils.js
@@ -13,6 +13,8 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */
+const E = require('./enums')
+
 const generateProxyURL = (type, urlElements, opts) => {
   if (!opts || !opts.doipProxyHostname) {
     return null
@@ -37,13 +39,13 @@ const generateProxyURL = (type, urlElements, opts) => {
 
 const generateClaim = (fingerprint, format) => {
   switch (format) {
-    case 'uri':
+    case E.ClaimFormat.URI:
       return `openpgp4fpr:${fingerprint}`
       break
-    case 'message':
+    case E.ClaimFormat.MESSAGE:
       return `[Verifying my OpenPGP key: openpgp4fpr:${fingerprint}]`
       break
-    case 'fingerprint':
+    case E.ClaimFormat.FINGERPRINT:
       return fingerprint
       break
     default: