diff --git a/mug/src/main/java/com/google/mu/util/StringFormat.java b/mug/src/main/java/com/google/mu/util/StringFormat.java
index f456f33514..5c315b84ff 100644
--- a/mug/src/main/java/com/google/mu/util/StringFormat.java
+++ b/mug/src/main/java/com/google/mu/util/StringFormat.java
@@ -375,7 +375,7 @@ public <R> R parseOrThrow(String input, BiFunction<? super String, ? super Strin
 
   /**
    * Similar to {@link #parseOrThrow(String, BiFunction)}, but parses {@code input} and applies
-   * {@code mapper} with the <em>2</em> placeholder values in this format string.
+   * {@code mapper} with the <em>3</em> placeholder values in this format string.
    *
    * <p>For example:
    *