diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/controllers/ChallengeController.java b/service/src/main/java/org/whispersystems/textsecuregcm/controllers/ChallengeController.java
index b9c9623e9..e79682742 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/controllers/ChallengeController.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/controllers/ChallengeController.java
@@ -31,6 +31,8 @@ import jakarta.ws.rs.core.Context;
 import jakarta.ws.rs.core.MediaType;
 import jakarta.ws.rs.core.Response;
 import java.io.IOException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.whispersystems.textsecuregcm.auth.AuthenticatedDevice;
 import org.whispersystems.textsecuregcm.entities.AnswerCaptchaChallengeRequest;
 import org.whispersystems.textsecuregcm.entities.AnswerChallengeRequest;
@@ -52,6 +54,8 @@ public class ChallengeController {
   private final RateLimitChallengeManager rateLimitChallengeManager;
   private final ChallengeConstraintChecker challengeConstraintChecker;
 
+  private static final Logger logger = LoggerFactory.getLogger(ChallengeController.class);
+
   private static final String CHALLENGE_RESPONSE_COUNTER_NAME = name(ChallengeController.class, "challengeResponse");
   private static final String CHALLENGE_TYPE_TAG = "type";
 
@@ -85,8 +89,8 @@ public class ChallengeController {
       description = "If present, an positive integer indicating the number of seconds before a subsequent attempt could succeed"))
   public Response handleChallengeResponse(@Auth final AuthenticatedDevice auth,
       @Valid final AnswerChallengeRequest answerRequest,
-      @Context ContainerRequestContext requestContext,
-      @HeaderParam(HttpHeaders.USER_AGENT) final String userAgent) throws RateLimitExceededException, IOException {
+      @Context final ContainerRequestContext requestContext,
+      @HeaderParam(HttpHeaders.USER_AGENT) final String userAgent) throws RateLimitExceededException {
 
     final Account account = accountsManager.getByAccountIdentifier(auth.accountIdentifier())
         .orElseThrow(() -> new WebApplicationException(Response.Status.UNAUTHORIZED));
@@ -103,12 +107,12 @@ public class ChallengeController {
           return Response.status(429).build();
         }
         rateLimitChallengeManager.answerPushChallenge(account, pushChallengeRequest.getChallenge());
-      } else if (answerRequest instanceof AnswerCaptchaChallengeRequest captchaChallengeRequest) {
+      } else if (answerRequest instanceof final AnswerCaptchaChallengeRequest captchaChallengeRequest) {
         tags = tags.and(CHALLENGE_TYPE_TAG, "captcha");
 
         final String remoteAddress = (String) requestContext.getProperty(
             RemoteAddressFilter.REMOTE_ADDRESS_ATTRIBUTE_NAME);
-        boolean success = rateLimitChallengeManager.answerCaptchaChallenge(
+        final boolean success = rateLimitChallengeManager.answerCaptchaChallenge(
             account,
             captchaChallengeRequest.getCaptcha(),
             remoteAddress,
@@ -122,6 +126,9 @@ public class ChallengeController {
       } else {
         tags = tags.and(CHALLENGE_TYPE_TAG, "unrecognized");
       }
+    } catch (final IOException e) {
+      logger.error("error assessing captcha during challenge response handling", e);
+      return Response.status(Response.Status.SERVICE_UNAVAILABLE).build();
     } finally {
       Metrics.counter(CHALLENGE_RESPONSE_COUNTER_NAME, tags).increment();
     }
diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/controllers/VerificationController.java b/service/src/main/java/org/whispersystems/textsecuregcm/controllers/VerificationController.java
index dc625eefb..e193b1f47 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/controllers/VerificationController.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/controllers/VerificationController.java
@@ -493,7 +493,7 @@ public class VerificationController {
           .increment();
 
     } catch (final IOException e) {
-      logger.error("error assessing captcha", e);
+      logger.error("error assessing captcha during registration verification", e);
       throw new ServerErrorException(Response.Status.SERVICE_UNAVAILABLE, e);
     }