diff --git a/HISTORY.md b/HISTORY.md
index 390a963..9458c12 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -1,5 +1,9 @@
 # History
 
+## 1.3.9 (2018-01-10)
+
+- Clarify documentation
+
 ## 1.3.7 (2018-11-28)
 
 - Clarify extra options and move to main CLI entry point
diff --git a/ffmpeg_normalize/_version.py b/ffmpeg_normalize/_version.py
index ffa9fec..d427944 100644
--- a/ffmpeg_normalize/_version.py
+++ b/ffmpeg_normalize/_version.py
@@ -1 +1 @@
-__version__ = "1.3.8"
+__version__ = "1.3.9"