diff --git a/ChangeLog b/ChangeLog
index c8c392eac4..135ff6b518 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2017-08-22  Joseph Myers  <joseph@codesourcery.com>
+
+	* assert/Makefile [$(have-cxx-thread_local)]: Move conditional
+	variable definitions above inclusion of ../Rules.
+
 2017-10-11  Florian Weimer  <fweimer@redhat.com>
 
 	[BZ #22078]
diff --git a/assert/Makefile b/assert/Makefile
index 9ec1be81a9..222ab516f0 100644
--- a/assert/Makefile
+++ b/assert/Makefile
@@ -27,8 +27,6 @@ headers	:= assert.h
 routines := assert assert-perr __assert
 tests := test-assert test-assert-perr tst-assert-c++ tst-assert-g++
 
-include ../Rules
-
 ifeq ($(have-cxx-thread_local),yes)
 CFLAGS-tst-assert-c++.o = -std=c++11
 LDLIBS-tst-assert-c++ = -lstdc++
@@ -37,3 +35,5 @@ LDLIBS-tst-assert-g++ = -lstdc++
 else
 tests-unsupported += tst-assert-c++ tst-assert-g++
 endif
+
+include ../Rules