diff --git a/strings/split.py b/strings/split.py
index ed194ec69c2f..4a7f5b669645 100644
--- a/strings/split.py
+++ b/strings/split.py
@@ -17,8 +17,15 @@ def split(string: str, separator: str = " ") -> list:
 
     >>> split(";abbb;;c;", separator=';')
     ['', 'abbb', '', 'c', '']
+
+    >>> split("a--b--c", separator="--")
+    Traceback (most recent call last):
+    ValueError: separator must be a single character
     """
 
+    if len(separator) != 1:
+        raise ValueError("separator must be a single character")
+
     split_words = []
 
     last_index = 0