diff -up ./crypto/random/seed/GetEntropyRandomSeed.c.entropy ./crypto/random/seed/GetEntropyRandomSeed.c
--- ./crypto/random/seed/GetEntropyRandomSeed.c.entropy	2017-02-24 00:23:48.994554470 -0500
+++ ./crypto/random/seed/GetEntropyRandomSeed.c	2017-02-24 00:28:07.022641392 -0500
@@ -23,8 +23,9 @@
 
 #define GetEntropyRandomSeed_GLIBC_HAS_IT \
     (defined(__GNU_LIBRARY__) && defined(__GLIBC_PREREQ) && __GLIBC_PREREQ(2, 25))
-
-#if !defined(__OPENBSD__) && !GetEntropyRandomSeed_GLIBC_HAS_IT
+/* gcc warns against using defined() inside #define, so just copy definition */
+#if !defined(__OPENBSD__) && \
+!(defined(__GNU_LIBRARY__) && defined(__GLIBC_PREREQ) && __GLIBC_PREREQ(2, 25))
 static int getentropy(void *buf, size_t buflen)
 {
     int ret;