diff --git a/net/dcsctp/socket/dcsctp_socket_test.cc b/net/dcsctp/socket/dcsctp_socket_test.cc
index c542a9cd1a..33af2a15de 100644
--- a/net/dcsctp/socket/dcsctp_socket_test.cc
+++ b/net/dcsctp/socket/dcsctp_socket_test.cc
@@ -208,13 +208,19 @@ class DcSctpSocketTest : public testing::Test {
     } while (delivered_packet);
   }
 
+  void RunTimers(MockDcSctpSocketCallbacks& cb, DcSctpSocket& socket) {
+    for (;;) {
+      absl::optional<TimeoutID> timeout_id = cb.GetNextExpiredTimeout();
+      if (!timeout_id.has_value()) {
+        break;
+      }
+      socket.HandleTimeout(*timeout_id);
+    }
+  }
+
   void RunTimers() {
-    for (const auto timeout_id : cb_a_.RunTimers()) {
-      sock_a_.HandleTimeout(timeout_id);
-    }
-    for (const auto timeout_id : cb_z_.RunTimers()) {
-      sock_z_.HandleTimeout(timeout_id);
-    }
+    RunTimers(cb_a_, sock_a_);
+    RunTimers(cb_z_, sock_z_);
   }
 
   const DcSctpOptions options_;
@@ -1025,9 +1031,7 @@ TEST_F(DcSctpSocketTest, PassingHighWatermarkWillOnlyAcceptCumAckTsn) {
 
   // The receiver might have moved into delayed ack mode.
   cb_z2.AdvanceTime(options.rto_initial);
-  for (const auto timeout_id : cb_z2.RunTimers()) {
-    sock_z2.HandleTimeout(timeout_id);
-  }
+  RunTimers(cb_z2, sock_z2);
 
   EXPECT_THAT(
       cb_z2.ConsumeSentPacket(),
@@ -1066,9 +1070,7 @@ TEST_F(DcSctpSocketTest, PassingHighWatermarkWillOnlyAcceptCumAckTsn) {
 
   // The receiver might have moved into delayed ack mode.
   cb_z2.AdvanceTime(options.rto_initial);
-  for (const auto timeout_id : cb_z2.RunTimers()) {
-    sock_z2.HandleTimeout(timeout_id);
-  }
+  RunTimers(cb_z2, sock_z2);
 
   EXPECT_THAT(
       cb_z2.ConsumeSentPacket(),
diff --git a/net/dcsctp/socket/heartbeat_handler_test.cc b/net/dcsctp/socket/heartbeat_handler_test.cc
index 58dbcff4b2..20c1d465db 100644
--- a/net/dcsctp/socket/heartbeat_handler_test.cc
+++ b/net/dcsctp/socket/heartbeat_handler_test.cc
@@ -45,6 +45,17 @@ class HeartbeatHandlerTest : public testing::Test {
         timer_manager_([this]() { return callbacks_.CreateTimeout(); }),
         handler_("log: ", options_, &context_, &timer_manager_) {}
 
+  void AdvanceTime(DurationMs duration) {
+    callbacks_.AdvanceTime(duration);
+    for (;;) {
+      absl::optional<TimeoutID> timeout_id = callbacks_.GetNextExpiredTimeout();
+      if (!timeout_id.has_value()) {
+        break;
+      }
+      timer_manager_.HandleTimeout(*timeout_id);
+    }
+  }
+
   const DcSctpOptions options_;
   NiceMock<MockDcSctpSocketCallbacks> callbacks_;
   NiceMock<MockContext> context_;
@@ -75,10 +86,7 @@ TEST_F(HeartbeatHandlerTest, RepliesToHeartbeatRequests) {
 }
 
 TEST_F(HeartbeatHandlerTest, SendsHeartbeatRequestsOnIdleChannel) {
-  callbacks_.AdvanceTime(options_.heartbeat_interval);
-  for (TimeoutID id : callbacks_.RunTimers()) {
-    timer_manager_.HandleTimeout(id);
-  }
+  AdvanceTime(options_.heartbeat_interval);
 
   // Grab the request, and make a response.
   std::vector<uint8_t> payload = callbacks_.ConsumeSentPacket();
@@ -101,22 +109,15 @@ TEST_F(HeartbeatHandlerTest, SendsHeartbeatRequestsOnIdleChannel) {
 }
 
 TEST_F(HeartbeatHandlerTest, IncreasesErrorIfNotAckedInTime) {
-  callbacks_.AdvanceTime(options_.heartbeat_interval);
-
   DurationMs rto(105);
   EXPECT_CALL(context_, current_rto).WillOnce(Return(rto));
-  for (TimeoutID id : callbacks_.RunTimers()) {
-    timer_manager_.HandleTimeout(id);
-  }
+  AdvanceTime(options_.heartbeat_interval);
 
   // Validate that a request was sent.
   EXPECT_THAT(callbacks_.ConsumeSentPacket(), Not(IsEmpty()));
 
   EXPECT_CALL(context_, IncrementTxErrorCounter).Times(1);
-  callbacks_.AdvanceTime(rto);
-  for (TimeoutID id : callbacks_.RunTimers()) {
-    timer_manager_.HandleTimeout(id);
-  }
+  AdvanceTime(rto);
 }
 
 }  // namespace
diff --git a/net/dcsctp/socket/mock_dcsctp_socket_callbacks.h b/net/dcsctp/socket/mock_dcsctp_socket_callbacks.h
index bad1aa697d..289da7a4d1 100644
--- a/net/dcsctp/socket/mock_dcsctp_socket_callbacks.h
+++ b/net/dcsctp/socket/mock_dcsctp_socket_callbacks.h
@@ -134,7 +134,9 @@ class MockDcSctpSocketCallbacks : public DcSctpSocketCallbacks {
   void AdvanceTime(DurationMs duration_ms) { now_ = now_ + duration_ms; }
   void SetTime(TimeMs now) { now_ = now; }
 
-  std::vector<TimeoutID> RunTimers() { return timeout_manager_.RunTimers(); }
+  absl::optional<TimeoutID> GetNextExpiredTimeout() {
+    return timeout_manager_.GetNextExpiredTimeout();
+  }
 
  private:
   TimeMs now_ = TimeMs(0);
diff --git a/net/dcsctp/socket/stream_reset_handler_test.cc b/net/dcsctp/socket/stream_reset_handler_test.cc
index 4f9b7434d6..6168f16312 100644
--- a/net/dcsctp/socket/stream_reset_handler_test.cc
+++ b/net/dcsctp/socket/stream_reset_handler_test.cc
@@ -119,8 +119,12 @@ class StreamResetHandlerTest : public testing::Test {
 
   void AdvanceTime(DurationMs duration) {
     callbacks_.AdvanceTime(kRto);
-    for (TimeoutID timeout_id : callbacks_.RunTimers()) {
-      timer_manager_.HandleTimeout(timeout_id);
+    for (;;) {
+      absl::optional<TimeoutID> timeout_id = callbacks_.GetNextExpiredTimeout();
+      if (!timeout_id.has_value()) {
+        break;
+      }
+      timer_manager_.HandleTimeout(*timeout_id);
     }
   }
 
diff --git a/net/dcsctp/timer/fake_timeout.h b/net/dcsctp/timer/fake_timeout.h
index 265b34edfa..ada4754a27 100644
--- a/net/dcsctp/timer/fake_timeout.h
+++ b/net/dcsctp/timer/fake_timeout.h
@@ -18,6 +18,7 @@
 #include <utility>
 #include <vector>
 
+#include "absl/types/optional.h"
 #include "net/dcsctp/public/timeout.h"
 
 namespace dcsctp {
@@ -73,15 +74,20 @@ class FakeTimeoutManager {
     return timer;
   }
 
-  std::vector<TimeoutID> RunTimers() {
+  // NOTE: This can't return a vector, as calling EvaluateHasExpired requires
+  // calling socket->HandleTimeout directly afterwards, as the owning Timer
+  // still believes it's running, and it needs to be updated to set
+  // Timer::is_running_ to false before you operate on the Timer or Timeout
+  // again.
+  absl::optional<TimeoutID> GetNextExpiredTimeout() {
     TimeMs now = get_time_();
     std::vector<TimeoutID> expired_timers;
     for (auto& timer : timers_) {
       if (timer->EvaluateHasExpired(now)) {
-        expired_timers.push_back(timer->timeout_id());
+        return timer->timeout_id();
       }
     }
-    return expired_timers;
+    return absl::nullopt;
   }
 
  private:
diff --git a/net/dcsctp/timer/timer_test.cc b/net/dcsctp/timer/timer_test.cc
index 719d73e891..82b92ef395 100644
--- a/net/dcsctp/timer/timer_test.cc
+++ b/net/dcsctp/timer/timer_test.cc
@@ -32,8 +32,13 @@ class TimerTest : public testing::Test {
   void AdvanceTimeAndRunTimers(DurationMs duration) {
     now_ = now_ + duration;
 
-    for (TimeoutID timeout_id : timeout_manager_.RunTimers()) {
-      manager_.HandleTimeout(timeout_id);
+    for (;;) {
+      absl::optional<TimeoutID> timeout_id =
+          timeout_manager_.GetNextExpiredTimeout();
+      if (!timeout_id.has_value()) {
+        break;
+      }
+      manager_.HandleTimeout(*timeout_id);
     }
   }