diff --git a/cabal.project b/cabal.project
index aa69af815..16927d02c 100644
--- a/cabal.project
+++ b/cabal.project
@@ -1,7 +1,8 @@
 packages: gitit.cabal
 tests: True
 flags: +plugins
-constraints: bytestring >= 0.12.2.0
+constraints: hashable < 1.5.0.0
+-- hashable 1.5 depends on base >= 4.18
 
 package pandoc
   flags: +embed_data_files
diff --git a/gitit.cabal b/gitit.cabal
index 1c2e4dfb9..37c8f4ad1 100644
--- a/gitit.cabal
+++ b/gitit.cabal
@@ -184,7 +184,7 @@ Library
 Executable           gitit
   hs-source-dirs:    .
   main-is:           gitit.hs
-  build-depends:     base >= 4.9 && < 5,
+  build-depends:     base >= 4.14 && < 5,
                      gitit,
                      mtl,
                      hslogger,