diff --git a/documentation/pestpp_users_guide_v5.1.7.docx b/documentation/pestpp_users_guide_v5.1.9.docx
similarity index 69%
rename from documentation/pestpp_users_guide_v5.1.7.docx
rename to documentation/pestpp_users_guide_v5.1.9.docx
index 50db6d4ae..5197a9a45 100644
Binary files a/documentation/pestpp_users_guide_v5.1.7.docx and b/documentation/pestpp_users_guide_v5.1.9.docx differ
diff --git a/documentation/pestpp_users_manual.md b/documentation/pestpp_users_manual.md
index b340f5289..1379452aa 100644
--- a/documentation/pestpp_users_manual.md
+++ b/documentation/pestpp_users_manual.md
@@ -1,7 +1,7 @@
 
  <img src="./media/image1.png" style="width:6.26806in;height:1.68194in" alt="A close up of a purple sign Description automatically generated" />
 
-# <a id='s1' />Version 5.1.7
+# <a id='s1' />Version 5.1.9
 
 <img src="./media/image2.png" style="width:6.26806in;height:3.05972in" />
 
@@ -70,7 +70,7 @@ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLI
 
 # Table of Contents
 
-- [Version 5.1.7](#s1)
+- [Version 5.1.9](#s1)
 - [Acknowledgements](#s2)
 - [Preface](#s3)
 - [License](#s4)