diff --git a/speciesData.py b/speciesData.py
index b4985da434f0de1a17f2ba7b5cb6aa5ceb9d0576..de246d7eb798f7ca1d36b90ba6b159fae7fe8765 100755
--- a/speciesData.py
+++ b/speciesData.py
@@ -39,11 +39,11 @@ class SpeciesData:
         if parameters_dictionary["data"]["genome_version"] == "":
             self.genome_version = "1.0"
         else:
-            self.genome_version = parameters_dictionary["data"]["genome_version"]
+            self.genome_version = str(parameters_dictionary["data"]["genome_version"])
         if parameters_dictionary["data"]["ogs_version"] == "":
             self.ogs_version = "1.0"
         else:
-            self.ogs_version = parameters_dictionary["data"]["ogs_version"]
+            self.ogs_version = str(parameters_dictionary["data"]["ogs_version"])
 
         # TODO: catch blocks if key is absent in input
         self.genome_path = parameters_dictionary["data"]["genome_path"]