diff --git a/src/Makefile.am b/src/Makefile.am
index c2967d4..419fbb4 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -153,19 +153,31 @@ $(GENERATED_WGL_INCLUDES): $(GENERATED_WGL_SOURCE)
 
 $(GENERATED_GL_SOURCE): $(srcdir)/gen_dispatch.py $(top_srcdir)/registry/gl.xml
 	@$(MKDIR_P) $(top_builddir)/include/epoxy
-	$(AM_V_GEN)$(PYTHON) $(srcdir)/gen_dispatch.py --dir $(top_builddir) $(top_srcdir)/registry/gl.xml
+	$(AM_V_GEN)$(PYTHON) $(srcdir)/gen_dispatch.py \
+		--srcdir $(top_builddir)/src \
+		--includedir $(top_builddir)/include/epoxy \
+		$(top_srcdir)/registry/gl.xml
 
 $(GENERATED_GLX_SOURCE): $(srcdir)/gen_dispatch.py $(top_srcdir)/registry/glx.xml
 	@$(MKDIR_P) $(top_builddir)/include/epoxy
-	$(AM_V_GEN)$(PYTHON) $(srcdir)/gen_dispatch.py --dir $(top_builddir) $(top_srcdir)/registry/glx.xml
+	$(AM_V_GEN)$(PYTHON) $(srcdir)/gen_dispatch.py \
+		--srcdir $(top_builddir)/src \
+		--includedir $(top_builddir)/include/epoxy \
+		$(top_srcdir)/registry/glx.xml
 
 $(GENERATED_EGL_SOURCE): $(srcdir)/gen_dispatch.py $(top_srcdir)/registry/egl.xml
 	@$(MKDIR_P) $(top_builddir)/include/epoxy
-	$(AM_V_GEN)$(PYTHON) $(srcdir)/gen_dispatch.py --dir $(top_builddir) $(top_srcdir)/registry/egl.xml
+	$(AM_V_GEN)$(PYTHON) $(srcdir)/gen_dispatch.py \
+		--srcdir $(top_builddir)/src \
+		--includedir $(top_builddir)/include/epoxy \
+		$(top_srcdir)/registry/egl.xml
 
 $(GENERATED_WGL_SOURCE): $(srcdir)/gen_dispatch.py $(top_srcdir)/registry/wgl.xml
 	@$(MKDIR_P) $(top_builddir)/include/epoxy
-	$(AM_V_GEN)$(PYTHON) $(srcdir)/gen_dispatch.py --dir $(top_builddir) $(top_srcdir)/registry/wgl.xml
+	$(AM_V_GEN)$(PYTHON) $(srcdir)/gen_dispatch.py \
+		--srcdir $(top_builddir)/src \
+		--includedir $(top_builddir)/include/epoxy \
+		$(top_srcdir)/registry/wgl.xml
 
 EXTRA_DIST = \
 	gen_dispatch.py \
diff --git a/src/gen_dispatch.py b/src/gen_dispatch.py
index dfce596..283d965 100755
--- a/src/gen_dispatch.py
+++ b/src/gen_dispatch.py
@@ -836,11 +836,23 @@ class Generator(object):
 
 argparser = argparse.ArgumentParser(description='Generate GL dispatch wrappers.')
 argparser.add_argument('files', metavar='file.xml', nargs='+', help='GL API XML files to be parsed')
-argparser.add_argument('--dir', metavar='dir', required=True, help='Destination directory')
+argparser.add_argument('--srcdir', metavar='srcdir', required=False, help='Destination directory for source files')
+argparser.add_argument('--includedir', metavar='incdir', required=False, help='Destination director for header files')
+argparser.add_argument('--dir', metavar='dir', required=False, help='Destination directory')
 args = argparser.parse_args()
 
-srcdir = args.dir + '/src/'
-incdir = args.dir + '/include/epoxy/'
+if args.dir:
+    srcdir = args.dir
+    incdir = args.dir
+else:
+    srcdir = args.srcdir
+    incdir = args.includedir
+
+if not srcdir:
+    srcdir = os.getcwd()
+
+if not incdir:
+    incdir = os.getcwd()
 
 for file in args.files:
     name = os.path.basename(file).split('.xml')[0]
@@ -869,5 +881,5 @@ for file in args.files:
 
     generator.prepare_provider_enum()
 
-    generator.write_header(incdir + name + '_generated.h')
-    generator.write_source(srcdir + name + '_generated_dispatch.c')
+    generator.write_header(os.path.join(incdir, name + '_generated.h'))
+    generator.write_source(os.path.join(srcdir, name + '_generated_dispatch.c'))