diff --git a/soitool/coder.py b/soitool/coder.py
index 5212ce7b756bedf027e6275de9c60f3bf0b4a177..9060c4d1767f0d8907de8130b1f95dca596f2acf 100644
--- a/soitool/coder.py
+++ b/soitool/coder.py
@@ -26,12 +26,14 @@ def get_code(code_length, mode="ascii"):
     code = ""
     i = 0
 
-    characters = string.ascii_uppercase
-
-    if mode == "digits":
+    if mode == "ascii":
+        characters = string.ascii_uppercase
+    elif mode == "digits":
         characters = string.digits
     elif mode == "combo":
         characters = string.ascii_uppercase + string.digits
+    else:
+        raise ValueError("Invalid value for argument 'mode'")
 
     while i < code_length:
         letter = secrets.choice(characters)
@@ -71,8 +73,7 @@ def get_code_set(count, code_length, mode="ascii"):
 
 def get_code_length_needed(number_of_entries):
     """
-    Get code length needed to support one 
-    unique code for each entry.
+    Get code length needed to support one unique code for each entry.
 
     Parameters
     ----------
diff --git a/soitool/database.py b/soitool/database.py
index 32731e82222adaf0d75ba528907224c27b11ed68..dcd2bf54bebaf60b8ef2194bef7e8cbc27fb4cef 100644
--- a/soitool/database.py
+++ b/soitool/database.py
@@ -72,7 +72,7 @@ class Database:
         file.close()
 
         # Generate codes
-        code_len = soitool.coder.get_code_length(len(entries))
+        code_len = soitool.coder.get_code_length_needed(len(entries))
         codes = soitool.coder.get_code_set(len(entries), code_len)
 
         # Insert data in db
@@ -180,7 +180,7 @@ class Database:
         # Get number of entries
         number_of_entries = len(words)
         # Generate new codes
-        code_len = soitool.coder.get_code_length(number_of_entries)
+        code_len = soitool.coder.get_code_length_needed(number_of_entries)
         codes = soitool.coder.get_code_set(number_of_entries, code_len)
         # Statement for update
         stmt = "UPDATE CodeBook SET Code = ?"
@@ -214,9 +214,11 @@ class Database:
         if number_of_entries < 2:
             actual_code_len = len(self.conn.execute(stmt).fetchall()[1][0])
         else:
-            actual_code_len = soitool.coder.get_code_length(0)
+            actual_code_len = soitool.coder.get_code_length_needed(0)
 
-        needed_code_len = soitool.coder.get_code_length(number_of_entries)
+        needed_code_len = soitool.coder.get_code_length_needed(
+            number_of_entries
+        )
 
         if actual_code_len < needed_code_len:
             self.update_codebook()
diff --git a/test/test_coder.py b/test/test_coder.py
index eca8a15d8627ae56946d9bf790df2cfbd190b937..d51e3575286a88442b5d996366c540ceb4f69872 100644
--- a/test/test_coder.py
+++ b/test/test_coder.py
@@ -44,9 +44,13 @@ class CoderTest(unittest.TestCase):
 
     def test_get_code_length(self):
         """Test return correct codelenght."""
-        self.assertEqual(self.LEN, coder.get_code_length(0))
-        self.assertEqual(self.LEN, coder.get_code_length(self.COMBINATIONS))
-        self.assertEqual(3, coder.get_code_length(self.COMBINATIONS + 1))
+        self.assertEqual(self.LEN, coder.get_code_length_needed(0))
+        self.assertEqual(
+            self.LEN, coder.get_code_length_needed(self.COMBINATIONS)
+        )
+        self.assertEqual(
+            3, coder.get_code_length_needed(self.COMBINATIONS + 1)
+        )
 
 
 if __name__ == "__main__":
diff --git a/test/test_database.py b/test/test_database.py
index dbd64c52e8ac2a07688f86663448165a09b10e35..842dc9a48136412028ed5fccbf4dadb25e422cd7 100644
--- a/test/test_database.py
+++ b/test/test_database.py
@@ -4,7 +4,7 @@ from pathlib import Path
 import unittest
 import json
 from soitool.database import Database
-from soitool.coder import get_code_length
+from soitool.coder import get_code_length_needed
 
 TESTDATA_PATH = Path(__file__).parent.parent / "soitool/testdata"
 
@@ -96,7 +96,7 @@ class DatabaseTest(unittest.TestCase):
         self.assertEqual(len(expected), len(actual))
 
         # Get expected length of codes
-        code_len = get_code_length(len(expected))
+        code_len = get_code_length_needed(len(expected))
 
         # Check equality
         for i, entry in enumerate(expected):
@@ -138,7 +138,7 @@ class DatabaseTest(unittest.TestCase):
         # Compare lenth
         self.assertEqual(len(expected), len(actual))
         # Get expected length of codes
-        code_len = get_code_length(len(expected))
+        code_len = get_code_length_needed(len(expected))
         # Compare contents
         for i, entry in enumerate(expected):
             self.assertEqual(entry["word"], actual[i]["word"])
@@ -163,7 +163,7 @@ class DatabaseTest(unittest.TestCase):
         # Compare lenght
         self.assertEqual(len(expected), len(actual))
         # Get expected length of codes
-        code_len = get_code_length(len(expected))
+        code_len = get_code_length_needed(len(expected))
         # Compare contents
         for i, entry in enumerate(expected):
             self.assertEqual(entry["word"], actual[i]["word"])
@@ -217,7 +217,7 @@ class DatabaseTest(unittest.TestCase):
             code_len = len(
                 self.database.conn.execute(stmt_code).fetchall()[0][0]
             )
-            self.assertEqual(code_len, get_code_length(numb_of_entries))
+            self.assertEqual(code_len, get_code_length_needed(numb_of_entries))
 
         else:
             print("ERROR: Database is not 675 entries long, cant run test")