diff --git a/src/main/java/org/signal/registration/ratelimit/SendSmsVerificationCodeRateLimiter.java b/src/main/java/org/signal/registration/ratelimit/SendSmsVerificationCodeRateLimiter.java
index 7c65d938..9890d660 100644
--- a/src/main/java/org/signal/registration/ratelimit/SendSmsVerificationCodeRateLimiter.java
+++ b/src/main/java/org/signal/registration/ratelimit/SendSmsVerificationCodeRateLimiter.java
@@ -14,6 +14,8 @@
 import java.util.Comparator;
 import java.util.List;
 import java.util.Optional;
+import java.util.stream.Stream;
+
 import org.signal.registration.rpc.MessageTransport;
 import org.signal.registration.session.FailedSendReason;
 import org.signal.registration.session.RegistrationSession;
@@ -41,16 +43,22 @@ protected int getPriorAttemptCount(final RegistrationSession session) {
         .filter(attempt -> attempt.getMessageTransport() == MessageTransport.MESSAGE_TRANSPORT_SMS)
         .count() +
             (int) session.getFailedAttemptsList().stream()
-                    .filter(attempt -> attempt.getMessageTransport() == MessageTransport.MESSAGE_TRANSPORT_SMS
-                            && attempt.getFailedSendReason() != FailedSendReason.FAILED_SEND_REASON_UNAVAILABLE)
+                    .filter(attempt -> attempt.getMessageTransport() == MessageTransport.MESSAGE_TRANSPORT_SMS)
+                    .filter(attempt -> attempt.getFailedSendReason() != FailedSendReason.FAILED_SEND_REASON_UNAVAILABLE)
                     .count();
   }
 
   @Override
   protected Optional<Instant> getLastAttemptTime(final RegistrationSession session) {
-    return session.getRegistrationAttemptsList().stream()
-        .filter(attempt -> attempt.getMessageTransport() == MessageTransport.MESSAGE_TRANSPORT_SMS)
-        .map(attempt -> Instant.ofEpochMilli(attempt.getTimestampEpochMillis()))
-        .max(Comparator.naturalOrder());
+    return Stream.concat(
+            session.getRegistrationAttemptsList().stream()
+                    .filter(attempt -> attempt.getMessageTransport() == MessageTransport.MESSAGE_TRANSPORT_SMS)
+                    .map(attempt -> Instant.ofEpochMilli(attempt.getTimestampEpochMillis())),
+            session.getFailedAttemptsList().stream()
+                    .filter(attempt -> attempt.getMessageTransport() == MessageTransport.MESSAGE_TRANSPORT_SMS)
+                    .filter(attempt -> attempt.getFailedSendReason() != FailedSendReason.FAILED_SEND_REASON_UNAVAILABLE)
+                    .map(attempt -> Instant.ofEpochMilli(attempt.getTimestampEpochMillis()))
+            )
+            .max(Comparator.naturalOrder());
   }
 }
diff --git a/src/main/java/org/signal/registration/ratelimit/SendVoiceVerificationCodeRateLimiter.java b/src/main/java/org/signal/registration/ratelimit/SendVoiceVerificationCodeRateLimiter.java
index c9bc5b08..2b4bdd1d 100644
--- a/src/main/java/org/signal/registration/ratelimit/SendVoiceVerificationCodeRateLimiter.java
+++ b/src/main/java/org/signal/registration/ratelimit/SendVoiceVerificationCodeRateLimiter.java
@@ -18,6 +18,7 @@
 import java.util.List;
 import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
+import java.util.stream.Stream;
 
 @Singleton
 @Named("send-voice-verification-code")
@@ -76,16 +77,21 @@ protected int getPriorAttemptCount(final RegistrationSession session) {
         .filter(attempt -> attempt.getMessageTransport() == MessageTransport.MESSAGE_TRANSPORT_VOICE)
         .count() +
             (int) session.getFailedAttemptsList().stream()
-                    .filter(attempt -> attempt.getMessageTransport() == MessageTransport.MESSAGE_TRANSPORT_VOICE
-                            && attempt.getFailedSendReason() != FailedSendReason.FAILED_SEND_REASON_UNAVAILABLE)
+                    .filter(attempt -> attempt.getMessageTransport() == MessageTransport.MESSAGE_TRANSPORT_VOICE)
+                    .filter(attempt -> attempt.getFailedSendReason() != FailedSendReason.FAILED_SEND_REASON_UNAVAILABLE)
                     .count();
   }
 
   @Override
   protected Optional<Instant> getLastAttemptTime(final RegistrationSession session) {
-    return session.getRegistrationAttemptsList().stream()
-        .filter(attempt -> attempt.getMessageTransport() == MessageTransport.MESSAGE_TRANSPORT_VOICE)
-        .map(attempt -> Instant.ofEpochMilli(attempt.getTimestampEpochMillis()))
+    return Stream.concat(
+            session.getRegistrationAttemptsList().stream()
+                    .filter(attempt -> attempt.getMessageTransport() == MessageTransport.MESSAGE_TRANSPORT_VOICE)
+                    .map(attempt -> Instant.ofEpochMilli(attempt.getTimestampEpochMillis())),
+            session.getFailedAttemptsList().stream()
+                    .filter(attempt -> attempt.getMessageTransport() == MessageTransport.MESSAGE_TRANSPORT_VOICE)
+                    .filter(attempt -> attempt.getFailedSendReason() != FailedSendReason.FAILED_SEND_REASON_UNAVAILABLE)
+                    .map(attempt -> Instant.ofEpochMilli(attempt.getTimestampEpochMillis())))
         .max(Comparator.naturalOrder());
   }
 }
diff --git a/src/test/java/org/signal/registration/ratelimit/SendSmsVerificationCodeRateLimiterTest.java b/src/test/java/org/signal/registration/ratelimit/SendSmsVerificationCodeRateLimiterTest.java
index abb28acc..7f791482 100644
--- a/src/test/java/org/signal/registration/ratelimit/SendSmsVerificationCodeRateLimiterTest.java
+++ b/src/test/java/org/signal/registration/ratelimit/SendSmsVerificationCodeRateLimiterTest.java
@@ -130,6 +130,16 @@ void getLastAttemptTime() {
             .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_VOICE)
             .setTimestampEpochMillis(System.currentTimeMillis())
             .build())
+        .addFailedAttempts(FailedSendAttempt.newBuilder()
+            .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_SMS)
+            .setFailedSendReason(FailedSendReason.FAILED_SEND_REASON_UNAVAILABLE)
+            .setTimestampEpochMillis(System.currentTimeMillis())
+            .build())
+        .addFailedAttempts(FailedSendAttempt.newBuilder()
+            .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_VOICE)
+            .setFailedSendReason(FailedSendReason.FAILED_SEND_REASON_REJECTED)
+            .setTimestampEpochMillis(System.currentTimeMillis())
+            .build())
         .build()));
 
     final long firstTimestamp = 37;
@@ -143,6 +153,15 @@ void getLastAttemptTime() {
                 .build())
             .build()));
 
+    assertEquals(Optional.of(Instant.ofEpochMilli(firstTimestamp)),
+        rateLimiter.getLastAttemptTime(RegistrationSession.newBuilder()
+            .addFailedAttempts(FailedSendAttempt.newBuilder()
+                .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_SMS)
+                .setFailedSendReason(FailedSendReason.FAILED_SEND_REASON_REJECTED)
+                .setTimestampEpochMillis(firstTimestamp)
+                .build())
+            .build()));
+
     assertEquals(Optional.of(Instant.ofEpochMilli(firstTimestamp)),
         rateLimiter.getLastAttemptTime(RegistrationSession.newBuilder()
             .addRegistrationAttempts(RegistrationAttempt.newBuilder()
@@ -153,6 +172,29 @@ void getLastAttemptTime() {
                 .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_VOICE)
                 .setTimestampEpochMillis(secondTimestamp)
                 .build())
+            .addFailedAttempts(FailedSendAttempt.newBuilder()
+                .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_SMS)
+                .setFailedSendReason(FailedSendReason.FAILED_SEND_REASON_UNAVAILABLE)
+                .setTimestampEpochMillis(secondTimestamp)
+                .build())
+            .addFailedAttempts(FailedSendAttempt.newBuilder()
+                .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_VOICE)
+                .setFailedSendReason(FailedSendReason.FAILED_SEND_REASON_REJECTED)
+                .setTimestampEpochMillis(secondTimestamp)
+                .build())
+            .build()));
+
+    assertEquals(Optional.of(Instant.ofEpochMilli(firstTimestamp)),
+        rateLimiter.getLastAttemptTime(RegistrationSession.newBuilder()
+            .addFailedAttempts(FailedSendAttempt.newBuilder()
+                .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_SMS)
+                .setFailedSendReason(FailedSendReason.FAILED_SEND_REASON_REJECTED)
+                .setTimestampEpochMillis(firstTimestamp)
+                .build())
+            .addRegistrationAttempts(RegistrationAttempt.newBuilder()
+                .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_VOICE)
+                .setTimestampEpochMillis(secondTimestamp)
+                .build())
             .build()));
 
     assertEquals(Optional.of(Instant.ofEpochMilli(secondTimestamp)),
@@ -166,6 +208,19 @@ void getLastAttemptTime() {
                 .setTimestampEpochMillis(secondTimestamp)
                 .build())
             .build()));
+
+    assertEquals(Optional.of(Instant.ofEpochMilli(secondTimestamp)),
+        rateLimiter.getLastAttemptTime(RegistrationSession.newBuilder()
+            .addRegistrationAttempts(RegistrationAttempt.newBuilder()
+                .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_SMS)
+                .setTimestampEpochMillis(firstTimestamp)
+                .build())
+            .addFailedAttempts(FailedSendAttempt.newBuilder()
+                .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_SMS)
+                .setFailedSendReason(FailedSendReason.FAILED_SEND_REASON_REJECTED)
+                .setTimestampEpochMillis(secondTimestamp)
+                .build())
+            .build()));
   }
 
   @Test
diff --git a/src/test/java/org/signal/registration/ratelimit/SendVoiceVerificationCodeRateLimiterTest.java b/src/test/java/org/signal/registration/ratelimit/SendVoiceVerificationCodeRateLimiterTest.java
index 29febdec..881717b3 100644
--- a/src/test/java/org/signal/registration/ratelimit/SendVoiceVerificationCodeRateLimiterTest.java
+++ b/src/test/java/org/signal/registration/ratelimit/SendVoiceVerificationCodeRateLimiterTest.java
@@ -221,6 +221,16 @@ void getLastAttemptTime() {
             .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_SMS)
             .setTimestampEpochMillis(System.currentTimeMillis())
             .build())
+        .addFailedAttempts(FailedSendAttempt.newBuilder()
+            .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_SMS)
+            .setFailedSendReason(FailedSendReason.FAILED_SEND_REASON_REJECTED)
+            .setTimestampEpochMillis(System.currentTimeMillis())
+            .build())
+        .addFailedAttempts(FailedSendAttempt.newBuilder()
+            .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_VOICE)
+            .setFailedSendReason(FailedSendReason.FAILED_SEND_REASON_UNAVAILABLE)
+            .setTimestampEpochMillis(System.currentTimeMillis())
+            .build())
         .build()));
 
     final long firstTimestamp = 37;
@@ -234,6 +244,15 @@ void getLastAttemptTime() {
                 .build())
             .build()));
 
+    assertEquals(Optional.of(Instant.ofEpochMilli(firstTimestamp)),
+        rateLimiter.getLastAttemptTime(RegistrationSession.newBuilder()
+            .addFailedAttempts(FailedSendAttempt.newBuilder()
+                .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_VOICE)
+                .setFailedSendReason(FailedSendReason.FAILED_SEND_REASON_REJECTED)
+                .setTimestampEpochMillis(firstTimestamp)
+                .build())
+            .build()));
+
     assertEquals(Optional.of(Instant.ofEpochMilli(firstTimestamp)),
         rateLimiter.getLastAttemptTime(RegistrationSession.newBuilder()
             .addRegistrationAttempts(RegistrationAttempt.newBuilder()
@@ -244,6 +263,29 @@ void getLastAttemptTime() {
                 .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_SMS)
                 .setTimestampEpochMillis(secondTimestamp)
                 .build())
+            .addFailedAttempts(FailedSendAttempt.newBuilder()
+                .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_VOICE)
+                .setFailedSendReason(FailedSendReason.FAILED_SEND_REASON_UNAVAILABLE)
+                .setTimestampEpochMillis(secondTimestamp)
+                .build())
+            .addFailedAttempts(FailedSendAttempt.newBuilder()
+                .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_SMS)
+                .setFailedSendReason(FailedSendReason.FAILED_SEND_REASON_REJECTED)
+                .setTimestampEpochMillis(secondTimestamp)
+                .build())
+            .build()));
+
+    assertEquals(Optional.of(Instant.ofEpochMilli(firstTimestamp)),
+        rateLimiter.getLastAttemptTime(RegistrationSession.newBuilder()
+            .addFailedAttempts(FailedSendAttempt.newBuilder()
+                .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_VOICE)
+                .setFailedSendReason(FailedSendReason.FAILED_SEND_REASON_REJECTED)
+                .setTimestampEpochMillis(firstTimestamp)
+                .build())
+            .addRegistrationAttempts(RegistrationAttempt.newBuilder()
+                .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_SMS)
+                .setTimestampEpochMillis(secondTimestamp)
+                .build())
             .build()));
 
     assertEquals(Optional.of(Instant.ofEpochMilli(secondTimestamp)),
@@ -257,5 +299,18 @@ void getLastAttemptTime() {
                 .setTimestampEpochMillis(secondTimestamp)
                 .build())
             .build()));
+
+    assertEquals(Optional.of(Instant.ofEpochMilli(secondTimestamp)),
+        rateLimiter.getLastAttemptTime(RegistrationSession.newBuilder()
+            .addRegistrationAttempts(RegistrationAttempt.newBuilder()
+                .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_VOICE)
+                .setTimestampEpochMillis(firstTimestamp)
+                .build())
+            .addFailedAttempts(FailedSendAttempt.newBuilder()
+                .setMessageTransport(MessageTransport.MESSAGE_TRANSPORT_VOICE)
+                .setFailedSendReason(FailedSendReason.FAILED_SEND_REASON_REJECTED)
+                .setTimestampEpochMillis(secondTimestamp)
+                .build())
+            .build()));
   }
 }