diff --git a/lambdas/aggregation/src/lambda_function.py b/lambdas/aggregation/src/lambda_function.py
index 6549507..2e0ab30 100644
--- a/lambdas/aggregation/src/lambda_function.py
+++ b/lambdas/aggregation/src/lambda_function.py
@@ -3,7 +3,6 @@
 from aws_xray_sdk.core import patch, xray_recorder
 
 from raster_analysis.boto import s3_client
-from raster_analysis.exceptions import QueryParseException
 from raster_analysis.globals import LOGGER
 
 patch(["boto3"])
@@ -95,8 +94,6 @@ def handler(event, context):
                 "failed_geometries_link": failed_geometries_link,
             },
         }
-    except QueryParseException as e:
-        return {"status": "failed", "message": str(e)}
     except Exception as e:
         LOGGER.exception(e)
         return {"status": "error", "message": str(e)}
diff --git a/lambdas/preprocessing/src/lambda_function.py b/lambdas/preprocessing/src/lambda_function.py
index 4fd02af..2b78575 100644
--- a/lambdas/preprocessing/src/lambda_function.py
+++ b/lambdas/preprocessing/src/lambda_function.py
@@ -9,7 +9,6 @@
 from shapely.wkb import dumps as wkb_dumps
 
 from raster_analysis.boto import s3_client
-from raster_analysis.exceptions import QueryParseException
 from raster_analysis.globals import LOGGER, S3_PIPELINE_BUCKET
 
 patch(["boto3"])
@@ -59,8 +58,6 @@ def handler(event, context):
             "geometries": {"bucket": S3_PIPELINE_BUCKET, "key": geom_prefix},
             "output": {"bucket": S3_PIPELINE_BUCKET, "prefix": output_prefix},
         }
-    except QueryParseException as e:
-        return {"status": "failed", "message": str(e), "geometries": {}, "output": {}}
     except Exception as e:
         LOGGER.exception(e)
         return {"status": "error", "message": str(e), "geometries": {}, "output": {}}
diff --git a/step_functions/process_list.json.tmpl b/step_functions/process_list.json.tmpl
index acdd4c2..7d49947 100644
--- a/step_functions/process_list.json.tmpl
+++ b/step_functions/process_list.json.tmpl
@@ -10,9 +10,30 @@
         "Payload.$": "$",
         "FunctionName": "${lambda_preprocessing_name}"
       },
-      "ResultSelector": {
-        "geometries.$": "$.Payload.geometries",
-        "output.$": "$.Payload.output"
+      "ResultPath": "$.PreprocOutput",
+      "Next": "Check status"
+    },
+    "Check status": {
+      "Type": "Choice",
+      "Choices": [
+        {
+	  "Variable": "$.PreprocOutput.status",
+	  "StringEquals": "error",
+	  "Next": "Error state"
+	}
+      ],
+      "Default": "Copy results"
+    },
+    "Error state": {
+      "Type": "Pass",
+      "OutputPath": "$.PreprocOutput",
+      "End": true
+    },
+    "Copy results": {
+      "Type": "Pass",
+      "Result": {
+        "geometries.$": "$.PreprocOutput.geometries",
+	"output.$", "$.PreprocOutput.output"
       },
       "ResultPath": "$.files",
       "Next": "Process List"