diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,9 @@
 # Changelog for horizon-spec
 
+## v0.6.1
+
+* Re-export MkModifiers constructor.
+
 ## v0.6
 
 * Change Overlay to wrap a `PackageSet` rather than a `PackageList`. The
diff --git a/horizon-spec.cabal b/horizon-spec.cabal
--- a/horizon-spec.cabal
+++ b/horizon-spec.cabal
@@ -1,6 +1,6 @@
 cabal-version:      3.0
 name:               horizon-spec
-version:            0.6
+version:            0.6.1
 synopsis:           Horizon Stable Package Set Type Definitions
 description:
   This package contains the type definitions for the Horizon stable package set (https://horizon-haskell.net). This is a schema used to define package sets sourcing from hackage and git.
diff --git a/src/Horizon/Spec.hs b/src/Horizon/Spec.hs
--- a/src/Horizon/Spec.hs
+++ b/src/Horizon/Spec.hs
@@ -10,7 +10,7 @@
   , HaskellSource(FromGit, FromHackage, FromTarball, FromLocal)
   , HorizonExport(MakePackageSet, MakeOverlay)
   , LocalSource(MkLocalSource, fromLocalSource)
-  , Modifiers(doJailbreak, doBenchmark, doCheck, enableProfiling, includeBenchmarks, includeExecutables, includeTests)
+  , Modifiers(MkModifiers, doJailbreak, doBenchmark, doCheck, enableProfiling, includeBenchmarks, includeExecutables, includeTests)
   , Name(MkName, fromName)
   , OverlayExportSettings(MkOverlayExportSettings, packagesDir, overlayFile, overlay)
   , OverlayFile(MkOverlayFile, fromOverlayFile)