diff --git a/factorial.py b/factorial.py
index 1d04ecd..d0215d8 100644
--- a/factorial.py
+++ b/factorial.py
@@ -5,5 +5,13 @@ def factorial(n):
     return n * factorial(n - 1)
 
 if __name__ == "__main__":
-    num = int(input("Enter a number: "))
-    print(f"The factorial of {num} is {factorial(num)}")
+    while True:
+        try:
+            num = int(input("Enter a positive integer: "))
+            if num < 0:
+                print("Please enter a positive integer.")
+            else:
+                print(f"The factorial of {num} is {factorial(num)}")
+                break  # Exit the loop if valid input
+        except ValueError:
+            print("Invalid input. Please enter a positive integer.")