diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 40102865bcec..0b15de79896f 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,7 @@
+2016-07-31  Jonathan Wakely  <jwakely@redhat.com>
+
+	* testsuite/26_numerics/headers/cstdlib/54686.c: Rename to 54686.cc.
+
 2016-07-29  Ville Voutilainen  <ville.voutilainen@gmail.com>
 
 	Implement C++17 variable templates for type traits.
diff --git a/libstdc++-v3/testsuite/26_numerics/headers/cstdlib/54686.c b/libstdc++-v3/testsuite/26_numerics/headers/cstdlib/54686.cc
similarity index 100%
rename from libstdc++-v3/testsuite/26_numerics/headers/cstdlib/54686.c
rename to libstdc++-v3/testsuite/26_numerics/headers/cstdlib/54686.cc