diff --git a/nameko_tracer/constants.py b/nameko_tracer/constants.py
index 155fd3e..c21ce3a 100644
--- a/nameko_tracer/constants.py
+++ b/nameko_tracer/constants.py
@@ -20,15 +20,14 @@ class Status(Enum):
 
 Use this name to configure entrypoint logging in ``LOGGING`` setting
 of Nameko config.
-
 """
 
+
 TRACE_KEY = 'nameko_trace'
 """ Name of the log record attribute holding the serialisable details
 
 Contains gathered entrypoint call and result details in serialisable
 and compact form.
-
 """
 
 
@@ -51,37 +50,38 @@ class Status(Enum):
 """ A key holding a dictionary of arguments passed to the entrypoint call
 """
 
+
 REQUEST_REDACTED_KEY = 'call_args_redacted'
 """
 A key holding a boolean value saying whether sensitive values of the
 entrypoint call arguments were redacted.
-
 """
 
+
 RESPONSE_KEY = 'response'
 """ A key holding serialisable return value of the entrypoint.
 """
 
+
 REQUEST_TRUNCATED_KEY = 'call_args_truncated'
 """
 A key holding a boolean value saying whether the call args data were
 truncated. Set by ``TruncateRequestFilter``.
-
 """
 
+
 RESPONSE_TRUNCATED_KEY = 'response_truncated'
 """
 A key holding a boolean value saying whether the result data were truncated.
 Set by ``TruncateResponseFilter``.
-
 """
 
+
 REQUEST_LENGTH_KEY = 'call_args_length'
 """ A key holding the original call args data length
 
 Set by ``TruncateRequestFilter`` to the original length of data in
 ``REQUEST_KEY``.
-
 """
 
 RESPONSE_LENGTH_KEY = 'response_length'
@@ -89,9 +89,9 @@ class Status(Enum):
 
 Set by ``TruncateResponseFilter`` to the original length of data in
 ``RESPONSE_KEY``.
-
 """
 
+
 RESPONSE_STATUS_KEY = 'response_status'
 """ A key holding the result status (a value of one of ``Status`` options)
 """
@@ -108,48 +108,56 @@ class Status(Enum):
 Set if the entrypoint resulted into an error
 """
 
+
 EXCEPTION_PATH_KEY = 'exception_path'
 """ A key holding exception path e.g. ``some.module.SomeError``
 
 Set if the entrypoint resulted into an error
 """
 
+
 EXCEPTION_VALUE_KEY = 'exception_value'
 """ A key holding string representation of exception raised
 
 Set if the entrypoint resulted into an error
 """
 
+
 EXCEPTION_ARGS_KEY = 'exception_args'
 """ A key holding a list of exception arguments
 
 Set if the entrypoint resulted into an error
 """
 
+
 EXCEPTION_TRACEBACK_KEY = 'exception_traceback'
 """ A key holding exception traceback string
 
 Set if the entrypoint resulted into an error
 """
 
+
 EXCEPTION_EXPECTED_KEY = 'exception_expected'
 """ A key holding a boolean saying whether the exception raised was one of
 errors expected by the entrypoint
-
 """
 
+
 SERVICE_NAME_KEY = 'service'
 """ A key holding the name of the service
 """
 
+
 ENTRYPOINT_NAME_KEY = 'entrypoint_name'
 """ A key holding the entrypoint service method name e.g. ``'get_user'``
 """
 
+
 ENTRYPOINT_TYPE_KEY = 'entrypoint_type'
 """ A key holding the entrypoint type name e.g. ``'Rpc'``.
 """
 
+
 CALL_ID_KEY = 'call_id'
 """ A key holding the unique ID of the entrypoint call
 """
@@ -158,10 +166,12 @@ class Status(Enum):
 """ A key holding the call ID stack ...
 """
 
+
 CONTEXT_DATA_KEY = 'context_data'
 """ A key holding the worker context data dictionary
 """
 
+
 DEFAULT_ADAPTERS = {
     'nameko.web.handlers.HttpRequestHandler': (
         'nameko_tracer.adapters.HttpRequestHandlerAdapter'),
@@ -171,8 +181,15 @@ class Status(Enum):
 
 Sets an override for Nameko built-in HttpRequestHandler. Extra overrides
 coming from config are merged in.
-
 """
 
+
 CONFIG_KEY = 'TRACER'
+""" Nameko config key holding tracer configuration
+"""
+
+
 ADAPTERS_CONFIG_KEY = 'ADAPTERS'
+"""
+A key holding adapters configuration in Nameko config (under ``CONFIG_KEY``)
+"""
diff --git a/nameko_tracer/filters.py b/nameko_tracer/filters.py
index a169c1c..694e19f 100644
--- a/nameko_tracer/filters.py
+++ b/nameko_tracer/filters.py
@@ -87,6 +87,10 @@ class TruncateResponseFilter(BaseTruncateFilter):
     lifecycle_stage = constants.Stage.response
 
     def truncate(self, data):
+
+        if constants.RESPONSE_KEY not in data:
+            return data
+
         result = utils.serialise_to_string(data[constants.RESPONSE_KEY])
         length = len(result)
         if length > self.max_len:
diff --git a/setup.py b/setup.py
index e43fbb4..0c0a1da 100644
--- a/setup.py
+++ b/setup.py
@@ -3,7 +3,7 @@
 
 setup(
     name='nameko-tracer',
-    version='1.0.5',
+    version='1.0.6',
     description='Nameko extension logging entrypoint processing metrics',
     author='student.com',
     author_email='wearehiring@student.com',
diff --git a/tests/test_filters.py b/tests/test_filters.py
index 26cbe68..98fba63 100644
--- a/tests/test_filters.py
+++ b/tests/test_filters.py
@@ -205,6 +205,30 @@ def test_truncate_response_to_string_casting(
     assert data[constants.RESPONSE_KEY] == expected_response_out
 
 
+def test_truncate_response_ignores_error_response(handler, logger):
+
+    filter_ = filters.TruncateResponseFilter(entrypoints=['^spam'], max_len=5)
+
+    logger.addFilter(filter_)
+
+    extra = {
+        constants.TRACE_KEY: {
+            constants.STAGE_KEY: constants.Stage.response.value,
+            constants.ENTRYPOINT_NAME_KEY: 'spam',
+            constants.RESPONSE_STATUS_KEY: constants.Status.error.value,
+        },
+    }
+
+    logger.info('response', extra=extra)
+
+    data = getattr(handler.log_record, constants.TRACE_KEY)
+
+    assert constants.RESPONSE_TRUNCATED_KEY not in data
+    assert constants.RESPONSE_LENGTH_KEY not in data
+    assert constants.REQUEST_TRUNCATED_KEY not in data
+    assert constants.REQUEST_LENGTH_KEY not in data
+
+
 def test_truncate_request_ignores_response_data(handler, logger):
 
     filter_ = filters.TruncateRequestFilter(entrypoints=['^spam'], max_len=5)