diff --git a/qmake/generators/unix/unixmake2.cpp b/qmake/generators/unix/unixmake2.cpp
index 4069b14..e583419 100644
--- a/qmake/generators/unix/unixmake2.cpp
+++ b/qmake/generators/unix/unixmake2.cpp
@@ -1546,26 +1546,38 @@ UnixMakefileGenerator::writePkgConfigFile()     // ### does make sense only for
     project->variables()["ALL_DEPS"].append(fname);
     QTextStream t(&ft);
 
-    QString prefix = pkgConfigPrefix();
-    QString libDir = project->first("QMAKE_PKGCONFIG_LIBDIR");
-    if(libDir.isEmpty())
-	libDir = prefix + "/lib";
-    QString includeDir = project->first("QMAKE_PKGCONFIG_INCDIR");
-    if(includeDir.isEmpty())
-	includeDir = prefix + "/include";
-    QString pluginsDir = project->first("QMAKE_PKGCONFIG_PLUGINS");
-    if(pluginsDir.isEmpty())
-	pluginsDir = prefix + "/plugins";
-    QString translationsDir = qInstallPathTranslations();
-    if(translationsDir.isEmpty())
-    translationsDir = prefix + "/translations";
-
-    t << "prefix=" << prefix << endl;
-    t << "exec_prefix=${prefix}\n"
-      << "libdir=" << pkgConfigFixPath(libDir) << "\n"
-      << "includedir=" << pkgConfigFixPath(includeDir) << "\n"
-      << "translationsdir=" << pkgConfigFixPath(translationsDir) << endl;
-    t << "pluginsdir=" << pkgConfigFixPath(pluginsDir) << endl;               // non-standard entry. Provides path for plugins
+	QString prefix = pkgConfigPrefix();
+	QString libDir = qInstallPathLibs();
+	if (libDir.isEmpty())
+	{
+		libDir = prefix + "/lib";
+	}
+	QString includeDir = qInstallPathHeaders();
+	if (includeDir.isEmpty())
+	{
+		includeDir = prefix + "/include";
+	}
+	QString pluginsDir = qInstallPathPlugins();
+	if (pluginsDir.isEmpty())
+	{
+		pluginsDir = prefix + "/plugins";
+	}
+	QString translationsDir = qInstallPathTranslations();
+	if (translationsDir.isEmpty())
+	{
+		translationsDir = prefix + "/translations";
+	}
+
+	t << "prefix=" << prefix << endl
+	  << "exec_prefix=${prefix}" << endl
+	  << "libdir=" << pkgConfigFixPath(libDir) << endl
+	  << "includedir=" << pkgConfigFixPath(includeDir) << endl
+	  // non-standard entry. Provides path for plugins
+	  << "pluginsdir=" << pkgConfigFixPath(pluginsDir) << endl
+	  // non-standard entry. Provides path for translations
+	  << "translationsdir=" << pkgConfigFixPath(translationsDir) << endl
+	  << endl;
+
     // non-standard entry. Provides useful info normally only
     // contained in the internal .qmake.cache file
     t << varGlue("CONFIG", "qt_config=", " ", "") << endl << endl;