diff --git a/src/connectors/captcha.ts b/src/connectors/captcha.ts
index 56f9a10239..d1110e8892 100644
--- a/src/connectors/captcha.ts
+++ b/src/connectors/captcha.ts
@@ -45,7 +45,7 @@ async function start() {
 
   let decodedData: any;
   try {
-    decodedData = JSON.parse(b64Decode(data));
+    decodedData = JSON.parse(b64Decode(data, true));
   } catch (e) {
     error("Cannot parse data.");
     return;
diff --git a/src/connectors/common.ts b/src/connectors/common.ts
index c822dc2b2d..a8855f1d4b 100644
--- a/src/connectors/common.ts
+++ b/src/connectors/common.ts
@@ -15,7 +15,11 @@ export function getQsParam(name: string) {
   return decodeURIComponent(results[2].replace(/\+/g, " "));
 }
 
-export function b64Decode(str: string) {
+export function b64Decode(str: string, spaceAsPlus = false) {
+  if (spaceAsPlus) {
+    str = str.replace(/ /g, "+");
+  }
+
   return decodeURIComponent(
     Array.prototype.map
       .call(atob(str), (c: string) => {