diff --git a/chepy/modules/encryptionencoding.py b/chepy/modules/encryptionencoding.py
index 3985268..6ed823f 100644
--- a/chepy/modules/encryptionencoding.py
+++ b/chepy/modules/encryptionencoding.py
@@ -84,9 +84,9 @@ def _convert_key(
         if iv_format == "base64" or iv_format == "b64":
             iv = base64.b64decode(iv)
         if iv_format == "utf-8" or iv_format == "utf8":
-            iv = key.decode().encode("utf-8")
+            iv = iv.decode().encode("utf-8")
         if iv_format == "latin-1":
-            iv = key.decode().encode("latin-1")
+            iv = iv.decode().encode("latin-1")
         if iv_format == "raw":
             iv = iv
         else:
diff --git a/tests/test_encryptionencoding.py b/tests/test_encryptionencoding.py
index 911ead9..b595a92 100644
--- a/tests/test_encryptionencoding.py
+++ b/tests/test_encryptionencoding.py
@@ -412,6 +412,10 @@ def test_aes_encrypt():
         .o
         == b"hello"
     )
+    assert (
+        Chepy('hello')
+        .aes_encrypt(key='supersecret!!!!!', key_format='utf8', iv='abcdefghijklmnop', iv_format='utf-8')
+        .to_hex().o == b'd18c2cba21d2eef40c9ed4771a9b320e')
 
 
 def test_aes_decrypt():