diff --git a/Doc/tut/tut.tex b/Doc/tut/tut.tex
index 03dd267..608388b 100644
--- a/Doc/tut/tut.tex
+++ b/Doc/tut/tut.tex
@@ -1228,7 +1228,7 @@
 
 \begin{verbatim}
 >>> def fib(n):    # write Fibonacci series up to n
-...     "Print a Fibonacci series up to n"
+...     """Print a Fibonacci series up to n."""
 ...     a, b = 0, 1
 ...     while b < n:
 ...         print b,
@@ -1306,7 +1306,7 @@
 
 \begin{verbatim}
 >>> def fib2(n): # return Fibonacci series up to n
-...     "Return a list containing the Fibonacci series up to n"
+...     """Return a list containing the Fibonacci series up to n."""
 ...     result = []
 ...     a, b = 0, 1
 ...     while b < n: