diff --git a/README.md b/README.md
index c331608..3ded25b 100644
--- a/README.md
+++ b/README.md
@@ -19,6 +19,7 @@ The object returned by a service provider consists of:
   - uri           (string: the URI containing the proof to be by humans and machines)
   - fetch         (string: see below)
   - useProxy      (boolean: should the request be sent using a proxy)
+  - format        (string: [json, text])
 - claim           (object)
   - fingerprint   (string: the fingerprint that verifies the claim if found in the proof)
   - format        (string: see below [uri, message, fingerprint])
diff --git a/src/serviceproviders/dns.js b/src/serviceproviders/dns.js
index d90895e..c622893 100644
--- a/src/serviceproviders/dns.js
+++ b/src/serviceproviders/dns.js
@@ -31,7 +31,8 @@ const processURI = (uri, opts) => {
     proof: {
       uri: `https://dns.shivering-isles.com/dns-query?name=${match[1]}&type=TXT`,
       fetch: null,
-      useProxy: false
+      useProxy: false,
+      format: 'json'
     },
     claim: {
       fingerprint: null,
diff --git a/src/serviceproviders/hackernews.js b/src/serviceproviders/hackernews.js
index e0d32b4..63c493e 100644
--- a/src/serviceproviders/hackernews.js
+++ b/src/serviceproviders/hackernews.js
@@ -31,7 +31,8 @@ const processURI = (uri, opts) => {
     proof: {
       uri: `https://hacker-news.firebaseio.com/v0/user/${match[1]}.json`,
       fetch: null,
-      useProxy: true
+      useProxy: true,
+      format: 'json'
     },
     claim: {
       fingerprint: null,
diff --git a/src/serviceproviders/twitter.js b/src/serviceproviders/twitter.js
index 1116f14..670b65c 100644
--- a/src/serviceproviders/twitter.js
+++ b/src/serviceproviders/twitter.js
@@ -31,7 +31,8 @@ const processURI = (uri, opts) => {
     proof: {
       uri: uri,
       fetch: `https://mobile.twitter.com/${match[1]}/status/${match[2]}`,
-      useProxy: false
+      useProxy: false,
+      format: 'text'
     },
     claim: {
       fingerprint: null,
diff --git a/src/serviceproviders/xmpp.js b/src/serviceproviders/xmpp.js
index 5cc28ba..3d7b215 100644
--- a/src/serviceproviders/xmpp.js
+++ b/src/serviceproviders/xmpp.js
@@ -33,7 +33,8 @@ const processURI = (uri, opts) => {
            ? `https://${opts.XMPP_VCARD_SERVER_DOMAIN}/api/vcard/${output.display}/DESC`
            : null,
       fetch: null,
-      useProxy: false
+      useProxy: false,
+      format: 'json'
     },
     claim: {
       fingerprint: null,