diff --git a/pephubclient/helpers.py b/pephubclient/helpers.py
index a9f764b..85979bf 100644
--- a/pephubclient/helpers.py
+++ b/pephubclient/helpers.py
@@ -16,6 +16,7 @@
 
 import requests
 from requests.exceptions import ConnectionError
+from urllib.parse import urlencode
 
 from ubiquerg import parse_registry_path
 from pydantic import ValidationError
@@ -76,11 +77,7 @@ def parse_query_param(pep_variables: dict) -> str:
         :param pep_variables: dict of query parameters
         :return: PEPHubClient variables transformed into string in correct format.
         """
-        parsed_variables = []
-
-        for variable_name, variable_value in pep_variables.items():
-            parsed_variables.append(f"{variable_name}={variable_value}")
-        return "?" + "&".join(parsed_variables)
+        return "?" + urlencode(pep_variables)
 
     @staticmethod
     def parse_header(jwt_data: Optional[str] = None) -> dict:
diff --git a/pephubclient/modules/sample.py b/pephubclient/modules/sample.py
index 0194af9..c8208d1 100644
--- a/pephubclient/modules/sample.py
+++ b/pephubclient/modules/sample.py
@@ -49,7 +49,9 @@ def get(
         if response.status_code == ResponseStatusCodes.OK:
             return self.decode_response(response, output_json=True)
         if response.status_code == ResponseStatusCodes.NOT_EXIST:
-            raise ResponseError("Sample does not exist.")
+            raise ResponseError(
+                f"Sample does not exist. Project: '{namespace}/{name}:{tag}'. Sample_name: '{sample_name}'"
+            )
         elif response.status_code == ResponseStatusCodes.INTERNAL_ERROR:
             raise ResponseError("Internal server error. Unexpected return value.")
         else: