diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/mappers/IOExceptionMapper.java b/service/src/main/java/org/whispersystems/textsecuregcm/mappers/IOExceptionMapper.java
index 54b6a5f3b..ea8b3ec1f 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/mappers/IOExceptionMapper.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/mappers/IOExceptionMapper.java
@@ -21,8 +21,19 @@ public class IOExceptionMapper implements ExceptionMapper<IOException> {
   public Response toResponse(IOException e) {
     if (!(e.getCause() instanceof java.util.concurrent.TimeoutException)) {
       logger.warn("IOExceptionMapper", e);
-    } else if (e.getCause().getMessage().startsWith("Idle timeout expired")) {
-      return Response.status(Response.Status.REQUEST_TIMEOUT).build();
+    } else {
+      // Some TimeoutExceptions are because the connection is idle, but are only distinguishable using the exception
+      // message
+      final String message = e.getCause().getMessage();
+      final boolean idleTimeout =
+          message != null &&
+              // org.eclipse.jetty.io.IdleTimeout
+              (message.startsWith("Idle timeout expired")
+                  // org.eclipse.jetty.http2.HTTP2Session
+                  || (message.startsWith("Idle timeout") && message.endsWith("elapsed")));
+      if (idleTimeout) {
+        return Response.status(Response.Status.REQUEST_TIMEOUT).build();
+      }
     }
 
     return Response.status(503).build();
diff --git a/service/src/test/java/org/whispersystems/textsecuregcm/mappers/IOExceptionMapperTest.java b/service/src/test/java/org/whispersystems/textsecuregcm/mappers/IOExceptionMapperTest.java
new file mode 100644
index 000000000..c307f30bc
--- /dev/null
+++ b/service/src/test/java/org/whispersystems/textsecuregcm/mappers/IOExceptionMapperTest.java
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2024 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.whispersystems.textsecuregcm.mappers;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.io.IOException;
+import java.util.concurrent.TimeoutException;
+import java.util.stream.Stream;
+import javax.ws.rs.core.Response;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+class IOExceptionMapperTest {
+
+  @ParameterizedTest
+  @MethodSource
+  void testExceptionParsing(final IOException exception, final int expectedStatus) {
+
+    try (Response response = new IOExceptionMapper().toResponse(exception)) {
+      assertEquals(expectedStatus, response.getStatus());
+    }
+  }
+
+  static Stream<Arguments> testExceptionParsing() {
+    return Stream.of(
+        Arguments.of(new IOException(), 503),
+        Arguments.of(new IOException(new TimeoutException("A timeout")), 503),
+        Arguments.of(new IOException(new TimeoutException()), 503),
+        Arguments.of(new IOException(new TimeoutException("Idle timeout 30000 ms elapsed")), 408),
+        Arguments.of(new IOException(new TimeoutException("Idle timeout expired")), 408),
+        Arguments.of(new IOException(new RuntimeException(new TimeoutException("Idle timeout expired"))), 503),
+        Arguments.of(new IOException(new TimeoutException("Idle timeout of another kind expired")), 503)
+    );
+  }
+
+}