diff --git a/setup.cfg b/setup.cfg
index f4b65ac..30e7efb 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -28,7 +28,7 @@ setup_requires =
 install_requires =
     aioca==1.4
     caproto==0.8.1
-    cothread==2.18.1
+    cothread==2.18.3
     epicscorelibs==7.0.7.99.0.0
     epicsdbbuilder==1.5
     nose2==0.12.0