diff --git a/libstdc++-v3/testsuite/17_intro/names.cc b/libstdc++-v3/testsuite/17_intro/names.cc
index 6b9a3639aad42b43a94b3b7cd8fab3234ade89ef..bea2d19ecba0129aa8995f26e192124e692393ed 100644
--- a/libstdc++-v3/testsuite/17_intro/names.cc
+++ b/libstdc++-v3/testsuite/17_intro/names.cc
@@ -282,6 +282,12 @@
 #undef y
 #endif
 
+#if defined (__linux__) && defined (__ia64__)
+// <bits/sigcontext.h> defines __ia64_fpreg::u
+// <sys/ucontext.h> defines __ia64_fpreg_mcontext::u
+#undef u
+#endif
+
 #if defined (__linux__) || defined (__gnu_hurd__)
 #if __has_include(<features.h>)
 #include <features.h>