diff --git a/python/samba/netcmd/domain_backup.py b/python/samba/netcmd/domain_backup.py
index 6cb0e512595..9c2c9e421f8 100644
--- a/python/samba/netcmd/domain_backup.py
+++ b/python/samba/netcmd/domain_backup.py
@@ -983,10 +983,16 @@ class cmd_domain_backup_offline(samba.netcmd.Command):
                     return
                 raise e
             raise copy_err
+
+        except FileNotFoundError as e:
+            # tdbbackup tool was not found.
+            raise CommandError(e.strerror, e)
+
         if not os.path.exists(backup_path):
             s = "tdbbackup said backup succeeded but {0} not found"
             raise CommandError(s.format(backup_path))
 
+
     def offline_mdb_copy(self, path):
         mdb_copy(path, path + self.backup_ext)
 
diff --git a/python/samba/tdb_util.py b/python/samba/tdb_util.py
index badfbd66bba..99b6e02e03f 100644
--- a/python/samba/tdb_util.py
+++ b/python/samba/tdb_util.py
@@ -32,6 +32,10 @@ def tdb_copy(file1, file2, readonly=False):
         toolpath = os.path.join(d, "tdbbackup")
         if os.path.exists(toolpath):
             break
+    else:
+        # we did not find a path to tdbbackup
+        raise FileNotFoundError(2, "could not find tdbbackup tool: "
+                                "is tdb-tools installed?")
 
     tdbbackup_cmd = [toolpath, "-s", ".copy.tdb", file1]
     if readonly: