diff --git a/ChangeLog b/ChangeLog
index 3a132751..c87c7d7b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+NEW IN WAF 2.0.18
+-----------------
+* Fix a deadlock with cython and subst tasks #2244
+* Fix rpath processing so that it no longer breaks dependency chains
+* Fix fast_partial.py failures on configuration tests
+* Fix duplicate -fno-strict-aliasing flags in Python compilation flags detection
+* Add a dependency scanner for assembly files (Gas/Yasm)
+* Add a QtTest example to demos/qt5/
+
 NEW IN WAF 2.0.17
 -----------------
 * Improve build performance on FreeBSD and Python3 #2241
diff --git a/waflib/TaskGen.py b/waflib/TaskGen.py
index 532b7d5c..f8f92bd5 100644
--- a/waflib/TaskGen.py
+++ b/waflib/TaskGen.py
@@ -905,7 +905,7 @@ def process_subst(self):
 		# paranoid safety measure for the general case foo.in->foo.h with ambiguous dependencies
 		for xt in HEADER_EXTS:
 			if b.name.endswith(xt):
-				tsk.ext_in = tsk.ext_in + ['.h']
+				tsk.ext_out = tsk.ext_out + ['.h']
 				break
 
 		inst_to = getattr(self, 'install_path', None)