diff --git a/waf_generator.py b/waf_generator.py
index 481b4fee..73b02a83 100755
--- a/waf_generator.py
+++ b/waf_generator.py
@@ -654,10 +654,11 @@ class ModuleManager(builder.ModuleManager):
         self.add('    for headers in header_paths:')
         self.add('        ipath = os.path.join(rtems.arch_bsp_include_path(bld.env.RTEMS_VERSION, bld.env.RTEMS_ARCH_BSP), headers[2])')
         self.add('        start_dir = bld.path.find_dir(headers[0])')
-        self.add('        bld.install_files("${PREFIX}/" + ipath,')
-        self.add('                          start_dir.ant_glob(headers[1]),')
-        self.add('                          cwd = start_dir,')
-        self.add('                          relative_trick = True)')
+        self.add('        if start_dir != None:')
+        self.add('            bld.install_files("${PREFIX}/" + ipath,')
+        self.add('                              start_dir.ant_glob(headers[1]),')
+        self.add('                              cwd = start_dir,')
+        self.add('                              relative_trick = True)')
         self.add('')
 
         self.add('    # Tests')