diff --git a/app/src/main/java/org/thoughtcrime/securesms/registration/RegistrationSessionProcessor.kt b/app/src/main/java/org/thoughtcrime/securesms/registration/RegistrationSessionProcessor.kt
index 066d62555..17c9684fb 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/registration/RegistrationSessionProcessor.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/registration/RegistrationSessionProcessor.kt
@@ -8,6 +8,7 @@ import org.whispersystems.signalservice.api.push.exceptions.MustRequestNewCodeEx
 import org.whispersystems.signalservice.api.push.exceptions.NoSuchSessionException
 import org.whispersystems.signalservice.api.push.exceptions.NonNormalizedPhoneNumberException
 import org.whispersystems.signalservice.api.push.exceptions.RateLimitException
+import org.whispersystems.signalservice.api.push.exceptions.TokenNotAcceptedException
 import org.whispersystems.signalservice.api.util.Preconditions
 import org.whispersystems.signalservice.internal.ServiceResponse
 import org.whispersystems.signalservice.internal.ServiceResponseProcessor
@@ -41,6 +42,10 @@ sealed class RegistrationSessionProcessor(response: ServiceResponse<Registration
     return PUSH_CHALLENGE_KEY == getChallenge()
   }
 
+  fun isTokenRejected(): Boolean {
+    return error is TokenNotAcceptedException
+  }
+
   fun isImpossibleNumber(): Boolean {
     return error is ImpossiblePhoneNumberException
   }
diff --git a/app/src/main/java/org/thoughtcrime/securesms/registration/fragments/EnterPhoneNumberFragment.java b/app/src/main/java/org/thoughtcrime/securesms/registration/fragments/EnterPhoneNumberFragment.java
index c3b04eb84..c2eff4981 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/registration/fragments/EnterPhoneNumberFragment.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/registration/fragments/EnterPhoneNumberFragment.java
@@ -299,6 +299,9 @@ public final class EnterPhoneNumberFragment extends LoggingFragment implements R
                                                               String.format(getString(R.string.RegistrationActivity_the_number_you_specified_s_is_invalid), viewModel.getNumber().getFullFormattedNumber()));
                                     } else if (processor.isNonNormalizedNumber()) {
                                       handleNonNormalizedNumberError(processor.getOriginalNumber(), processor.getNormalizedNumber(), mode);
+                                    } else if (processor.isTokenRejected()) {
+                                      Log.i(TAG, "The server did not accept the information.", processor.getError());
+                                      showErrorDialog(register.getContext(), getString(R.string.RegistrationActivity_we_need_to_verify_that_youre_human));
                                     } else {
                                       Log.i(TAG, "Unknown error during verification code request", processor.getError());
                                       showErrorDialog(register.getContext(), getString(R.string.RegistrationActivity_unable_to_connect_to_service));
diff --git a/app/src/main/java/org/thoughtcrime/securesms/registration/viewmodel/BaseRegistrationViewModel.java b/app/src/main/java/org/thoughtcrime/securesms/registration/viewmodel/BaseRegistrationViewModel.java
index 31059259b..f92f1e077 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/registration/viewmodel/BaseRegistrationViewModel.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/registration/viewmodel/BaseRegistrationViewModel.java
@@ -10,6 +10,7 @@ import com.google.i18n.phonenumbers.NumberParseException;
 import com.google.i18n.phonenumbers.PhoneNumberUtil;
 import com.google.i18n.phonenumbers.Phonenumber;
 
+import org.signal.core.util.logging.Log;
 import org.thoughtcrime.securesms.keyvalue.SignalStore;
 import org.thoughtcrime.securesms.pin.KbsRepository;
 import org.thoughtcrime.securesms.pin.TokenData;
@@ -36,6 +37,8 @@ import io.reactivex.rxjava3.core.Single;
  */
 public abstract class BaseRegistrationViewModel extends ViewModel {
 
+  private static final String TAG = Log.tag(BaseRegistrationViewModel.class);
+
   private static final String STATE_NUMBER                  = "NUMBER";
   private static final String STATE_REGISTRATION_SECRET     = "REGISTRATION_SECRET";
   private static final String STATE_VERIFICATION_CODE       = "TEXT_CODE_ENTERED";
@@ -280,10 +283,14 @@ public abstract class BaseRegistrationViewModel extends ViewModel {
     }
 
     if (hasCaptchaToken() && processor.captchaRequired()) {
-      return verifyAccountRepository.verifyCaptcha(sessionId, Objects.requireNonNull(getCaptchaToken()), e164, getRegistrationSecret())
+      Log.d(TAG, "Submitting completed captcha challenge");
+      final String captcha = Objects.requireNonNull(getCaptchaToken());
+      clearCaptchaResponse();
+      return verifyAccountRepository.verifyCaptcha(sessionId, captcha, e164, getRegistrationSecret())
                                     .map(RegistrationSessionProcessor.RegistrationSessionProcessorForSession::new);
     } else {
       String challenge = processor.getChallenge();
+      Log.d(TAG, "Handling challenge of type " + challenge);
       if (challenge != null) {
         switch (challenge) {
           case RegistrationSessionProcessor.PUSH_CHALLENGE_KEY:
diff --git a/libsignal/service/src/main/java/org/whispersystems/signalservice/api/push/exceptions/TokenNotAcceptedException.kt b/libsignal/service/src/main/java/org/whispersystems/signalservice/api/push/exceptions/TokenNotAcceptedException.kt
new file mode 100644
index 000000000..c8973e1ee
--- /dev/null
+++ b/libsignal/service/src/main/java/org/whispersystems/signalservice/api/push/exceptions/TokenNotAcceptedException.kt
@@ -0,0 +1,6 @@
+package org.whispersystems.signalservice.api.push.exceptions
+
+/**
+ * Exception representing that the submitted information was not accepted (e.g. the push challenge token or captcha did not match)
+ */
+class TokenNotAcceptedException : NonSuccessfulResponseCodeException(403)
diff --git a/libsignal/service/src/main/java/org/whispersystems/signalservice/internal/push/PushServiceSocket.java b/libsignal/service/src/main/java/org/whispersystems/signalservice/internal/push/PushServiceSocket.java
index 5ac79f4cf..867cd26c6 100644
--- a/libsignal/service/src/main/java/org/whispersystems/signalservice/internal/push/PushServiceSocket.java
+++ b/libsignal/service/src/main/java/org/whispersystems/signalservice/internal/push/PushServiceSocket.java
@@ -86,6 +86,7 @@ import org.whispersystems.signalservice.api.push.exceptions.RateLimitException;
 import org.whispersystems.signalservice.api.push.exceptions.RemoteAttestationResponseExpiredException;
 import org.whispersystems.signalservice.api.push.exceptions.ResumeLocationInvalidException;
 import org.whispersystems.signalservice.api.push.exceptions.ServerRejectedException;
+import org.whispersystems.signalservice.api.push.exceptions.TokenNotAcceptedException;
 import org.whispersystems.signalservice.api.push.exceptions.UnregisteredUserException;
 import org.whispersystems.signalservice.api.push.exceptions.UsernameIsNotAssociatedWithAnAccountException;
 import org.whispersystems.signalservice.api.push.exceptions.UsernameIsNotReservedException;
@@ -348,7 +349,7 @@ public class PushServiceSocket {
     String path = VERIFICATION_SESSION_PATH + "/" + sessionId;
 
     final UpdateVerificationSessionRequestBody requestBody = new UpdateVerificationSessionRequestBody(captchaToken, pushToken, pushChallengeToken, mcc, mnc);
-    try (Response response = makeServiceRequest(path, "PATCH", jsonRequestBody(JsonUtil.toJson(requestBody)), NO_HEADERS, new RegistrationSessionResponseHandler(), Optional.empty(), false)) {
+    try (Response response = makeServiceRequest(path, "PATCH", jsonRequestBody(JsonUtil.toJson(requestBody)), NO_HEADERS, new PatchRegistrationSessionResponseHandler(), Optional.empty(), false)) {
       return parseSessionMetadataResponse(response);
     }
   }
@@ -2543,6 +2544,35 @@ public class PushServiceSocket {
     }
   }
 
+
+  private static class PatchRegistrationSessionResponseHandler implements ResponseCodeHandler {
+
+    @Override
+    public void handle(int responseCode, ResponseBody body) throws NonSuccessfulResponseCodeException, PushNetworkException {
+      switch (responseCode) {
+        case 403:
+          throw new TokenNotAcceptedException();
+        case 404:
+          throw new NoSuchSessionException();
+        case 409:
+          RegistrationSessionMetadataJson response;
+          try {
+            response = JsonUtil.fromJson(body.string(), RegistrationSessionMetadataJson.class);
+          } catch (IOException e) {
+            Log.e(TAG, "Unable to read response body.", e);
+            throw new NonSuccessfulResponseCodeException(409);
+          }
+          if (response.pushChallengedRequired()) {
+            throw new PushChallengeRequiredException();
+          } else if (response.captchaRequired()) {
+            throw new CaptchaRequiredException();
+          } else {
+            throw new HttpConflictException();
+          }
+      }
+    }
+  }
+
   private static class RegistrationCodeRequestResponseHandler implements ResponseCodeHandler {
     @Override public void handle(int responseCode, ResponseBody body) throws NonSuccessfulResponseCodeException, PushNetworkException {
       switch (responseCode) {