diff --git a/esrally/driver/driver.py b/esrally/driver/driver.py
index 64086c4c5..aab67b1b9 100644
--- a/esrally/driver/driver.py
+++ b/esrally/driver/driver.py
@@ -2129,16 +2129,19 @@ def _parse_headers(e):
         # Some runners return a raw response, causing the 'error' property to be a string literal of the bytes/BytesIO object,
         # we should avoid bubbling that up
         # e.g. ApiError(413, '<_io.BytesIO object at 0xffffaf146a70>')
+        # errors="replace" so binary response bodies (e.g. OTLP ingest returns binary protobuf
+        # error frames) don't crash the driver with UnicodeDecodeError. Undecodable bytes become
+        # U+FFFD in the logged/recorded message.
         if isinstance(e.body, bytes):
             # could be an empty body
-            if error_body := e.body.decode("utf-8"):
+            if error_body := e.body.decode("utf-8", errors="replace"):
                 error_message = error_body
             else:
                 # to be consistent with an empty 'e.error'
                 error_message = str(None)
         elif isinstance(e.body, BytesIO):
             # could be an empty body
-            if error_body := e.body.read().decode("utf-8"):
+            if error_body := e.body.read().decode("utf-8", errors="replace"):
                 error_message = error_body
             else:
                 # to be consistent with an empty 'e.error'
@@ -2146,17 +2149,17 @@ def _parse_headers(e):
         # fallback to 'error' property if the body isn't bytes/BytesIO
         else:
             if isinstance(e.error, bytes):
-                error_message = e.error.decode("utf-8")
+                error_message = e.error.decode("utf-8", errors="replace")
             elif isinstance(e.error, BytesIO):
-                error_message = e.error.read().decode("utf-8")
+                error_message = e.error.read().decode("utf-8", errors="replace")
             else:
                 # if the 'error' is empty, we get back str(None)
                 error_message = e.error
 
         if isinstance(e.info, bytes):
-            error_info = e.info.decode("utf-8")
+            error_info = e.info.decode("utf-8", errors="replace")
         elif isinstance(e.info, BytesIO):
-            error_info = e.info.read().decode("utf-8")
+            error_info = e.info.read().decode("utf-8", errors="replace")
         else:
             error_info = e.info
 
diff --git a/tests/driver/driver_test.py b/tests/driver/driver_test.py
index 47c99afbc..acb70e5d7 100644
--- a/tests/driver/driver_test.py
+++ b/tests/driver/driver_test.py
@@ -1987,6 +1987,25 @@ async def test_execute_single_with_http_400_with_raw_response_body(self):
             await driver.execute_single(self.context_managed(runner), es, params, on_error=OnErrorBehavior.ABORT)
         assert exc.value.args[0] == ("Request returned an error. Error type: api, Description: Huge error, HTTP Status: 499")
 
+    @pytest.mark.asyncio
+    async def test_execute_single_with_http_400_with_non_utf8_raw_response_body(self):
+        es = None
+        params = None
+        body = io.BytesIO(b"\xff")
+        str_literal = str(body)
+        error_meta = elastic_transport.ApiResponseMeta(
+            status=400,
+            http_version="1.1",
+            headers=elastic_transport.HttpHeaders(),
+            duration=0.0,
+            node=elastic_transport.NodeConfig(scheme="http", host="localhost", port=9200),
+        )
+        runner = mock.AsyncMock(side_effect=elasticsearch.ApiError(message=str_literal, meta=error_meta, body=body))
+
+        with pytest.raises(exceptions.RallyAssertionError) as exc:
+            await driver.execute_single(self.context_managed(runner), es, params, on_error=OnErrorBehavior.ABORT)
+        assert exc.value.args[0] == ("Request returned an error. Error type: api, Description: �, HTTP Status: 400")
+
     @pytest.mark.asyncio
     async def test_execute_single_with_http_400(self):
         es = None