diff --git a/unit01_cipher_fundamentals/lab/README.md b/unit01_cipher_fundamentals/lab/README.md
index 4504558..40b1183 100644
--- a/unit01_cipher_fundamentals/lab/README.md
+++ b/unit01_cipher_fundamentals/lab/README.md
@@ -55,7 +55,7 @@ bGxveWRz
 01000001 01101110 01101011 01101100 01100101 00110001 00110010 00110011
 </pre>
 
-### A.5	The mod operatpor
+### A.5	The mod operator
 Using Python, what is the result of 53,431 (mod 453)?
 
 In Python, this is: