diff --git a/zlib.cabal b/zlib.cabal
index 90bf6c9..0b8e4f5 100644
--- a/zlib.cabal
+++ b/zlib.cabal
@@ -60,8 +60,8 @@ flag non-blocking-ffi
                avoids this unfairness, but with greater overall cost.
 
 flag pkg-config
-  default:     False
-  manual:      True
+  default:     True
+  manual:      False
   description: Use @pkg-config(1)@ to locate foreign @zlib@ library.
 
 flag bundled-c-zlib
@@ -103,7 +103,7 @@ library
   ghc-options:     -Wall -fwarn-tabs
   if flag(non-blocking-ffi)
     cpp-options:   -DNON_BLOCKING_FFI
-  if flag(pkg-config) && !impl(ghcjs) && !os(ghcjs)
+  if flag(pkg-config)
     -- NB: pkg-config is available on windows as well when using msys2
     pkgconfig-depends: zlib
   else