diff --git a/test/mkmf/test_pkg_config.rb b/test/mkmf/test_pkg_config.rb
index 72efb4ba81..f6a960c7d9 100644
--- a/test/mkmf/test_pkg_config.rb
+++ b/test/mkmf/test_pkg_config.rb
@@ -3,7 +3,7 @@ require_relative 'base'
 require 'shellwords'
 
 class TestMkmfPkgConfig < TestMkmf
-  PKG_CONFIG = find_executable0("pkg-config")
+  PKG_CONFIG = config_string("PKG_CONFIG") {|path| find_executable0(path)}
 
   def setup
     super
@@ -26,7 +26,7 @@ class TestMkmfPkgConfig < TestMkmf
         Cflags: -I${includedir}/cflags-I --cflags-other
       EOF
 
-      @pkg_config_path, ENV["PKG_CONFIG_PATH"] = ENV["PKG_CONFIG_PATH"], File.join(Dir.pwd, "fixtures")
+      @pkg_config_path, ENV["PKG_CONFIG_PATH"] = ENV["PKG_CONFIG_PATH"], @fixtures_dir
     end
   end