diff --git a/senfscons/InstallIncludes.py b/senfscons/InstallIncludes.py
index 8845fa8e0d4fe31a7a2ac4aedb155f5281cfe56b..d6fc72e6aea1351f2f93da13881fe62c077e9c6a 100644
--- a/senfscons/InstallIncludes.py
+++ b/senfscons/InstallIncludes.py
@@ -49,7 +49,7 @@ class Installer:
 
 def generator(target, source, env, for_signature):
     return [ SCons.Action.Action( Installer(trg, src),
-                                  SCons.Environment.installString([trg], [src], env) )
+                                  lambda a,b,c,s=SCons.Environment.installString([trg], [src], env):s )
              for trg, src in zip(target,source) ]
 
 InstallIncludes = SCons.Builder.Builder(emitter = emitter,