diff --git a/epdb/management/commands/bootstrap.py b/epdb/management/commands/bootstrap.py
index 70073e54..eb74385a 100644
--- a/epdb/management/commands/bootstrap.py
+++ b/epdb/management/commands/bootstrap.py
@@ -93,11 +93,12 @@ class Command(BaseCommand):
         """Create the six default licenses supported by enviPath"""
         cc_strings = ["by", "by-nc", "by-nc-nd", "by-nc-sa", "by-nd", "by-sa"]
         for cc_string in cc_strings:
-            new_license = License()
-            new_license.cc_string = cc_string
-            new_license.link = f"https://creativecommons.org/licenses/{cc_string}/4.0/"
-            new_license.image_link = f"https://licensebuttons.net/l/{cc_string}/4.0/88x31.png"
-            new_license.save()
+            if not License.objects.filter(cc_string=cc_string).exists():
+                new_license = License()
+                new_license.cc_string = cc_string
+                new_license.link = f"https://creativecommons.org/licenses/{cc_string}/4.0/"
+                new_license.image_link = f"https://licensebuttons.net/l/{cc_string}/4.0/88x31.png"
+                new_license.save()
 
     def import_package(self, data, owner):
         return PackageManager.import_legacy_package(