diff --git a/Library/Homebrew/shims/mac/super/pkg-config b/Library/Homebrew/shims/mac/super/pkg-config
index ceb5b1b775..cca704592f 100755
--- a/Library/Homebrew/shims/mac/super/pkg-config
+++ b/Library/Homebrew/shims/mac/super/pkg-config
@@ -1,5 +1,11 @@
 #!/bin/sh
 
-exec "$HOMEBREW_OPT/pkg-config/bin/pkg-config" \
+pkg_config="$HOMEBREW_OPT/pkg-config/bin/pkg-config"
+
+if [ -z "$HOMEBREW_SDKROOT" ]; then
+  exec "$pkg_config" "$@"
+fi
+
+exec "$pkg_config" \
   "--define-variable=homebrew_sdkroot=$HOMEBREW_SDKROOT" \
   "$@"