diff --git a/requirements.txt b/requirements.txt
index 885928c..53f4c9d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -8,7 +8,7 @@ click==7.0
 cryptography==2.3.1
 defusedxml==0.5.0
 dnspython==1.15.0
-exchangelib==1.12.0
+exchangelib==1.12.5
 flask==1.0.2
 future==0.16.0
 idna==2.7