2 files changed, 2 insertions, 0 deletions
diff --git a/README.md b/README.md
index 828c69f..c8d7cb7 100644
--- a/README.md
+++ b/README.md
@@ -204,6 +204,7 @@ Methods:
 * `DocumentConverter idPrefix(String idPrefix)`:
   a string to prepend to any generated IDs,
   such as those used by bookmarks, footnotes and endnotes.
+  Defaults to the empty string.
 
 #### `Result<T>`
 
diff --git a/src/main/java/org/zwobble/mammoth/DocumentConverter.java b/src/main/java/org/zwobble/mammoth/DocumentConverter.java
index b523bba..abd99bb 100644
--- a/src/main/java/org/zwobble/mammoth/DocumentConverter.java
+++ b/src/main/java/org/zwobble/mammoth/DocumentConverter.java
@@ -40,6 +40,7 @@ public class DocumentConverter {
     /**
      * A string to prepend to any generated IDs,
      * such as those used by bookmarks, footnotes and endnotes.
+     * Defaults to the empty string.
      */
     public DocumentConverter idPrefix(String idPrefix) {
         return new DocumentConverter(options.idPrefix(idPrefix));