diff --git a/process.cabal b/process.cabal
index 28d5cd82a783f13dc1c7a9645df29edb3f71ed1b..aaf232bc34323e045a772ee6ae316c1f0214cb6d 100644
--- a/process.cabal
+++ b/process.cabal
@@ -38,6 +38,7 @@ Library {
         runProcess.h
     install-includes:
         runProcess.h
+        processFlags.h
         HsProcessConfig.h
     if os(windows)
         build-depends: Win32 >=2.2.0.0