diff --git a/libs/pbd/wscript b/libs/pbd/wscript
index f6b53177e0..e7a297e4cd 100644
--- a/libs/pbd/wscript
+++ b/libs/pbd/wscript
@@ -152,7 +152,7 @@ def build(bld):
                           'LIBPBD_MAJOR_VERSION' : LIBPBD_MAJOR_VERSION})
 
     # Make signals_generated.h using signals.py
-    bld(rule = sys.executable + ' ${SRC} ${TGT}', source = 'pbd/signals.py', target = 'pbd/signals_generated.h', name="pbdsignals")
+    bld(rule = sys.executable + ' ${SRC} ${TGT}', source = 'pbd/signals.py', target = 'pbd/signals_generated.h', name="pbdsignals", features='use', ext_out=['.h'])
 
     # Library
     if bld.is_defined ('INTERNAL_SHARED_LIBS'):