diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8aae429ca478..b66ba2fee625 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2015-05-28  Mike Frysinger  <vapier@gentoo.org>
+
+	* config/nios2/linux.h (CPP_SPEC): Define.
+
 2015-05-28  Mike Frysinger  <vapier@gentoo.org>
 
 	* config/microblaze/linux.h (CPP_SPEC): Define.
diff --git a/gcc/config/nios2/linux.h b/gcc/config/nios2/linux.h
index 41cad943c2ca..f43f655e8606 100644
--- a/gcc/config/nios2/linux.h
+++ b/gcc/config/nios2/linux.h
@@ -26,6 +26,9 @@
     }                                           \
   while (0)
 
+#undef CPP_SPEC
+#define CPP_SPEC "%{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
+
 #define GLIBC_DYNAMIC_LINKER "/lib/ld-linux-nios2.so.1"
 
 #undef LINK_SPEC