diff --git a/src/cath.ts b/src/cath.ts
index 106b153..888d6de 100644
--- a/src/cath.ts
+++ b/src/cath.ts
@@ -10,6 +10,9 @@ export type CommonAccessTokenHeaderMap = Map<string, MatchMap>;
 export class CommonAccessTokenHeader {
   private cathMap: CommonAccessTokenHeaderMap = new Map();
 
+  /**
+   * Create a CATH claim from a dictionary with numbers as keys (labels)
+   */
   public static fromDictTags(dict: { [key: number]: any }) {
     const newDict: { [key: string]: any } = {};
     for (const headerTag in dict) {
@@ -23,6 +26,9 @@ export class CommonAccessTokenHeader {
     return CommonAccessTokenHeader.fromDict(newDict);
   }
 
+  /**
+   * Create a CATH claim from a dictionary with string as keys
+   */
   public static fromDict(dict: { [key: string]: any }) {
     const cath = new CommonAccessTokenHeader();
     for (const header in dict) {
@@ -35,6 +41,9 @@ export class CommonAccessTokenHeader {
     return cath;
   }
 
+  /**
+   * Create a CATH claim from a map with string as keys
+   */
   public static fromMap(map: CommonAccessTokenHeaderMap) {
     const cath = new CommonAccessTokenHeader();
     cath.cathMap = map;
diff --git a/src/catif.test.ts b/src/catif.test.ts
index 81185d2..a15637a 100644
--- a/src/catif.test.ts
+++ b/src/catif.test.ts
@@ -45,4 +45,25 @@ describe('Common Access Token If', () => {
       ]
     });
   });
+
+  test('can handle additional headers', async () => {
+    const basic = CommonAccessTokenIf.fromDict({
+      exp: [
+        307,
+        {
+          Location: 'https://auth.example.net/',
+          'x-custom-header': 'my-custom-header'
+        }
+      ]
+    });
+    expect(basic.toDict()).toEqual({
+      exp: [
+        307,
+        {
+          Location: 'https://auth.example.net/',
+          'x-custom-header': 'my-custom-header'
+        }
+      ]
+    });
+  });
 });
diff --git a/src/catif.ts b/src/catif.ts
index 46cbc89..9a23ab2 100644
--- a/src/catif.ts
+++ b/src/catif.ts
@@ -15,7 +15,11 @@ export type CatIfDictValue = {
 const valueToDict: { [key: string]: (value: any) => any } = {
   exp: (value) => {
     const [code, headers, kid] = value;
-    return [code, valueToDict['location'](headers.get('Location')), kid];
+    const dictHeaders: { [h: string]: any } = {};
+    headers.forEach((v: any, header: string) => {
+      dictHeaders[header] = valueToDict[header] ? valueToDict[header](v) : v;
+    });
+    return [code, dictHeaders, kid];
   },
   location: (value) => {
     if (typeof value === 'string') {
@@ -35,13 +39,20 @@ const valueToDict: { [key: string]: (value: any) => any } = {
 const dictToValue: { [key: string]: (value: any) => any } = {
   exp: (value) => {
     const [code, headers, kid] = value;
-    return [code, dictToValue['location'](headers['Location']), kid];
+    const map = new Map<string, any>();
+    for (const header in headers) {
+      map.set(
+        header,
+        dictToValue[header]
+          ? dictToValue[header](headers[header])
+          : headers[header]
+      );
+    }
+    return [code, map, kid];
   },
   location: (value) => {
     if (typeof value === 'string') {
-      const map = new Map<string, any>();
-      map.set('Location', value);
-      return map;
+      return value;
     } else {
       const [url, dict] = value;
       const lmap = new Map<string, any>();
@@ -51,9 +62,7 @@ const dictToValue: { [key: string]: (value: any) => any } = {
           dictToValue[key] ? dictToValue[key](dict[key]) : dict[key]
         );
       }
-      const map = new Map<string, any>();
-      map.set('Location', [url, lmap]);
-      return map;
+      return [url, lmap];
     }
   },
   catu: (value) => CommonAccessTokenUri.fromDict(value).payload