diff --git a/bindings/python/wscript b/bindings/python/wscript
index 8ca543b19..41e3a6407 100644
--- a/bindings/python/wscript
+++ b/bindings/python/wscript
@@ -346,7 +346,7 @@ class all_ns3_headers_taskgen(TaskGen.task_gen):
                         all_headers_inputs.append(node)
         assert all_headers_inputs
         all_headers_outputs = [self.path.find_or_declare("everything.h")]
-        task = self.create_task('gen_everything_h', self.env)
+        task = self.create_task('gen_everything_h', env=self.env)
         task.set_inputs(all_headers_inputs)
         task.set_outputs(all_headers_outputs)
 
diff --git a/src/wscript b/src/wscript
index 7b2b298ad..22b343d0e 100644
--- a/src/wscript
+++ b/src/wscript
@@ -138,7 +138,7 @@ class ns3header_taskgen(TaskGen.task_gen):
                 raise Utils.WafError("source ns3 header file %s not found" % (filename,))
             dst_node = ns3_dir_node.find_or_declare(os.path.basename(filename))
             assert dst_node is not None
-            task = self.create_task('ns3header', self.env)
+            task = self.create_task('ns3header', env=self.env)
             task.set_inputs([src_node])
             task.set_outputs([dst_node])
 
@@ -243,7 +243,7 @@ class ns3moduleheader_taskgen(TaskGen.task_gen):
         module_obj = self.bld.name_to_obj("ns3-" + self.module, self.env)
         assert module_obj is not None
         all_headers_outputs = [ns3_dir_node.find_or_declare("%s-module.h" % self.module)]
-        task = self.create_task('gen_ns3_module_header', self.env)
+        task = self.create_task('gen_ns3_module_header', env=self.env)
         task.set_inputs(all_headers_inputs)
         task.set_outputs(all_headers_outputs)
         task.module = self.module
diff --git a/waf b/waf
index 65ab0a8e3..d99146fa4 100755
Binary files a/waf and b/waf differ