diff --git a/src/doc/reference.md b/src/doc/reference.md
index 3d4791e916e6..9e4c01771d97 100644
--- a/src/doc/reference.md
+++ b/src/doc/reference.md
@@ -518,7 +518,7 @@ This last example is different because it is not possible to use the suffix
 syntax with a floating point literal ending in a period. `2.f64` would attempt
 to call a method named `f64` on `2`.
 
-##### Boolean literals
+#### Boolean literals
 
 The two values of the boolean type are written `true` and `false`.