diff --git a/doc/EXAMPLES.md b/doc/EXAMPLES.md
index 4c8668b..56bca12 100644
--- a/doc/EXAMPLES.md
+++ b/doc/EXAMPLES.md
@@ -17,6 +17,16 @@ e.g:
 
 `curl -X POST -H "Content-Type: application/json" --data '{"use_voice": true}' 'http://127.0.0.1:8080/v1/register/+431212131491291'`
 
+- Register a number (with captcha)
+
+  When you try to register a number, if you receive a response like `{"error":"Captcha required for verification (null)\n"}` then Signal is requiring a captcha. To register the number you must do the following:
+  1. Go to  [https://signalcaptchas.org/registration/generate.html](https://signalcaptchas.org/registration/generate.html)
+  2. Open the developer console
+  3. Find the line that looks like this: `Prevented navigation to “signalcaptcha://{captcha value}” due to an unknown protocol.` Copy the captcha value
+  4. Use it to make the registration call like this:
+
+  `curl -X POST -H "Content-Type: application/json" -d '{"captcha":"{captcha value}"}' 'http://127.0.0.1:8080/v1/register/<number>`
+
 - Verify the number using the code received via SMS/voice
 
   `curl -X POST -H "Content-Type: application/json" 'http://127.0.0.1:8080/v1/register/<number>/verify/<verification code>'`
diff --git a/doc/HOMEASSISTANT.md b/doc/HOMEASSISTANT.md
index c2bdb53..9d16e45 100644
--- a/doc/HOMEASSISTANT.md
+++ b/doc/HOMEASSISTANT.md
@@ -57,6 +57,14 @@ e.g:
 
 `curl -X POST -H "Content-Type: application/json" 'http://127.0.0.1:8080/v1/register/+431212131491291/verify/123-456'`
 
+When you try to register a number, if you receive a response like `{"error":"Captcha required for verification (null)\n"}` then Signal is requiring a captcha. To register the number you must do the following:
+1. Go to  [https://signalcaptchas.org/registration/generate.html](https://signalcaptchas.org/registration/generate.html)
+2. Open the developer console
+3. Find the line that looks like this: `Prevented navigation to “signalcaptcha://{captcha value}” due to an unknown protocol.` Copy the captcha value
+4. Use it to make the registration call like this:
+
+`curl -X POST -H "Content-Type: application/json" -d '{"captcha":"{captcha value}"}' 'http://127.0.0.1:8080/v1/register/<number>`
+
 ## Sending messages to Signal Messenger groups
 
 The `signal-cli-rest-api` docker container is also capable of sending messages to a Signal Messenger group.
diff --git a/src/api/api.go b/src/api/api.go
index 590522b..fbcc783 100644
--- a/src/api/api.go
+++ b/src/api/api.go
@@ -401,6 +401,7 @@ func (a *Api) About(c *gin.Context) {
 // @Success 201
 // @Failure 400 {object} Error
 // @Param number path string true "Registered Phone Number"
+// @Param data body RegisterNumberRequest false "Additional Settings"
 // @Router /v1/register/{number} [post]
 func (a *Api) RegisterNumber(c *gin.Context) {
 	number := c.Param("number")
@@ -452,7 +453,7 @@ func (a *Api) RegisterNumber(c *gin.Context) {
 // @Success 201 {string} string "OK"
 // @Failure 400 {object} Error
 // @Param number path string true "Registered Phone Number"
-// @Param data body VerifyNumberSettings true "Additional Settings"
+// @Param data body VerifyNumberSettings false "Additional Settings"
 // @Param token path string true "Verification Code"
 // @Router /v1/register/{number}/verify/{token} [post]
 func (a *Api) VerifyRegisteredNumber(c *gin.Context) {