diff --git a/src/ch04-03-slices.md b/src/ch04-03-slices.md
index ca7a8e4e2d..d064ff1343 100644
--- a/src/ch04-03-slices.md
+++ b/src/ch04-03-slices.md
@@ -8,6 +8,8 @@ Here’s a small programming problem: write a function that takes a string of
 words separated by spaces and returns the first word it finds in that string.
 If the function doesn’t find a space in the string, the whole string must be
 one word, so the entire string should be returned.
+The function doesn't need to handle input strings that have leading space
+characters.
 
 Let’s work through how we’d write the signature of this function without using
 slices, to understand the problem that slices will solve: