diff --git a/Cabal/src/Distribution/Simple/Program/Builtin.hs b/Cabal/src/Distribution/Simple/Program/Builtin.hs
index 1f3db0740f3..7ccc6393d86 100644
--- a/Cabal/src/Distribution/Simple/Program/Builtin.hs
+++ b/Cabal/src/Distribution/Simple/Program/Builtin.hs
@@ -400,4 +400,11 @@ pkgConfigProgram :: Program
 pkgConfigProgram =
   (simpleProgram "pkg-config")
     { programFindVersion = findProgramVersion "--version" id
+    , programPostConf = \_ pkgConfProg ->
+        let programOverrideEnv' =
+                 programOverrideEnv pkgConfProg
+              ++ [ ("PKG_CONFIG_ALLOW_SYSTEM_CFLAGS", Just "1")
+                 , ("PKG_CONFIG_ALLOW_SYSTEM_LIBS",   Just "1")
+                 ]
+        in pure $ pkgConfProg { programOverrideEnv = programOverrideEnv' }
     }