diff --git a/matterhorn.cabal b/matterhorn.cabal
index abca3df2..189ce1b4 100644
--- a/matterhorn.cabal
+++ b/matterhorn.cabal
@@ -11,7 +11,7 @@ maintainer:          matterhorn@galois.com
 copyright:           ©2016-2019 docs/AUTHORS.txt
 category:            Chat
 build-type:          Simple
-cabal-version:       >= 1.18
+cabal-version:       1.18
 tested-with:         GHC == 8.0.2, GHC == 8.2.2, GHC == 8.4.4, GHC == 8.6.5, GHC == 8.8.3
 
 data-files:          syntax/*.xml