diff --git a/compat/getentropy_linux.c b/compat/getentropy_linux.c
index 6b220be31..d9a5277a6 100644
--- a/compat/getentropy_linux.c
+++ b/compat/getentropy_linux.c
@@ -20,8 +20,11 @@
  * http://man.openbsd.org/getentropy.2
  */
 
+#include "config.h"
+/*
 #define	_POSIX_C_SOURCE	199309L
 #define	_GNU_SOURCE	1
+*/
 #include <sys/types.h>
 #include <sys/param.h>
 #include <sys/ioctl.h>
@@ -47,7 +50,15 @@
 #include <errno.h>
 #include <unistd.h>
 #include <time.h>
+#ifndef HAVE_NETTLE
 #include <openssl/sha.h>
+#else
+#include <nettle/sha.h>
+#define SHA512_CTX		struct sha512_ctx
+#define SHA512_Init(x)		sha512_init(x)
+#define SHA512_Update(x, b, s)	sha512_update(x, s, b)
+#define SHA512_Final(r, c)	sha512_digest(c, SHA512_DIGEST_SIZE, r)
+#endif
 
 #include <linux/types.h>
 #include <linux/random.h>
@@ -55,6 +66,9 @@
 #include <sys/auxv.h>
 #endif
 #include <sys/vfs.h>
+#ifndef MAP_ANON
+#define MAP_ANON MAP_ANONYMOUS
+#endif
 
 #define REPEAT 5
 #define min(a, b) (((a) < (b)) ? (a) : (b))
diff --git a/compat/getentropy_solaris.c b/compat/getentropy_solaris.c
index b80c84de9..0a03046d4 100644
--- a/compat/getentropy_solaris.c
+++ b/compat/getentropy_solaris.c
@@ -20,6 +20,7 @@
  * http://man.openbsd.org/getentropy.2
  */
 
+#include "config.h"
 #include <sys/types.h>
 #include <sys/param.h>
 #include <sys/ioctl.h>
@@ -32,7 +33,9 @@
 #include <sys/stat.h>
 #include <sys/time.h>
 #include <stdlib.h>
+#ifdef HAVE_STDINT_H
 #include <stdint.h>
+#endif
 #include <stdio.h>
 #include <link.h>
 #include <termios.h>
@@ -42,10 +45,14 @@
 #include <errno.h>
 #include <unistd.h>
 #include <time.h>
+#ifdef HAVE_SYS_SHA2_H
 #include <sys/sha2.h>
 #define SHA512_Init SHA512Init
 #define SHA512_Update SHA512Update
 #define SHA512_Final SHA512Final
+#else
+#include "openssl/sha.h"
+#endif
 
 #include <sys/vfs.h>
 #include <sys/statfs.h>
diff --git a/doc/Changelog b/doc/Changelog
index 0df61acbb..02ad18bbe 100644
--- a/doc/Changelog
+++ b/doc/Changelog
@@ -23,6 +23,12 @@
 	  OpenBSD, no changes but makes the file, comments, identical.
 	- Upgrade compat/getentropy_solaris.c to version 1.13 from OpenBSD.
 	- Upgrade compat/getentropy_osx.c to version 1.12 from OpenBSD.
+	- Changes to compat/getentropy files for,
+	  no link to openssl if using nettle, and hence config.h for
+	  HAVE_NETTLE variable.
+	  compat definition of MAP_ANON, for older systems.
+	  ifdef stdint.h inclusion for older systems.
+	  ifdef sha2.h inclusion for older systems.
 
 19 November 2019: Wouter
 	- Fix CVE-2019-18934, shell execution in ipsecmod.