diff --git a/mongoose.c b/mongoose.c
index bcf88097..97d5c17e 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -2802,18 +2802,16 @@ void mg_hexdump(const void *buf, size_t len) {
 #if defined(MG_ENABLE_MD5) && MG_ENABLE_MD5
 
 static void mg_byte_reverse(unsigned char *buf, unsigned longs) {
-/* Forrest: MD5 expect LITTLE_ENDIAN, swap if BIG_ENDIAN */
-#if BYTE_ORDER == BIG_ENDIAN
-  do {
-    uint32_t t = (uint32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
-                 ((unsigned) buf[1] << 8 | buf[0]);
-    *(uint32_t *) buf = t;
-    buf += 4;
-  } while (--longs);
-#else
-  (void) buf;
-  (void) longs;
-#endif
+  if (MG_BIG_ENDIAN) {
+    do {
+      uint32_t t = (uint32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
+                   ((unsigned) buf[1] << 8 | buf[0]);
+      *(uint32_t *) buf = t;
+      buf += 4;
+    } while (--longs);
+  } else {
+    (void) buf, (void) longs;  // Little endian. Do nothing
+  }
 }
 
 #define F1(x, y, z) (z ^ (x & (y ^ z)))
@@ -3646,11 +3644,11 @@ union char64long16 {
 #define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
 
 static uint32_t blk0(union char64long16 *block, int i) {
-/* Forrest: SHA expect BIG_ENDIAN, swap if LITTLE_ENDIAN */
-#if BYTE_ORDER == LITTLE_ENDIAN
-  block->l[i] =
-      (rol(block->l[i], 24) & 0xFF00FF00) | (rol(block->l[i], 8) & 0x00FF00FF);
-#endif
+  if (MG_BIG_ENDIAN) {
+  } else {
+    block->l[i] = (rol(block->l[i], 24) & 0xFF00FF00) |
+                  (rol(block->l[i], 8) & 0x00FF00FF);
+  }
   return block->l[i];
 }
 
diff --git a/mongoose.h b/mongoose.h
index 4737b89b..59c2c733 100644
--- a/mongoose.h
+++ b/mongoose.h
@@ -61,21 +61,6 @@ extern "C" {
 #define MG_ARCH MG_ARCH_RP2040
 #endif
 
-/*
- * clang with std=-c99 uses __LITTLE_ENDIAN, by default
- * while for ex, RTOS gcc - LITTLE_ENDIAN, by default
- * it depends on __USE_BSD, but let's have everything
- */
-#if !defined(BYTE_ORDER) && defined(__BYTE_ORDER)
-#define BYTE_ORDER __BYTE_ORDER
-#ifndef LITTLE_ENDIAN
-#define LITTLE_ENDIAN __LITTLE_ENDIAN
-#endif /* LITTLE_ENDIAN */
-#ifndef BIG_ENDIAN
-#define BIG_ENDIAN __LITTLE_ENDIAN
-#endif /* BIG_ENDIAN */
-#endif /* BYTE_ORDER */
-
 #if !defined(MG_ARCH)
 #include "mongoose_custom.h"  // keep this include
 #endif
@@ -85,6 +70,9 @@ extern "C" {
 #endif
 #endif  // !defined(MG_ARCH)
 
+// http://esr.ibiblio.org/?p=5095
+#define MG_BIG_ENDIAN (*(uint16_t *)"\0\xff" < 0x100)
+
 
 
 
@@ -659,7 +647,7 @@ int sscanf(const char *, const char *, ...);
 #endif
 
 #ifndef MG_ENABLE_MD5
-#define MG_ENABLE_MD5 0
+#define MG_ENABLE_MD5 1
 #endif
 
 // Set MG_ENABLE_WINSOCK=0 for Win32 builds with external IP stack (like LWIP)
diff --git a/src/arch.h b/src/arch.h
index a5b55394..70ae5a48 100644
--- a/src/arch.h
+++ b/src/arch.h
@@ -34,21 +34,6 @@
 #define MG_ARCH MG_ARCH_RP2040
 #endif
 
-/*
- * clang with std=-c99 uses __LITTLE_ENDIAN, by default
- * while for ex, RTOS gcc - LITTLE_ENDIAN, by default
- * it depends on __USE_BSD, but let's have everything
- */
-#if !defined(BYTE_ORDER) && defined(__BYTE_ORDER)
-#define BYTE_ORDER __BYTE_ORDER
-#ifndef LITTLE_ENDIAN
-#define LITTLE_ENDIAN __LITTLE_ENDIAN
-#endif /* LITTLE_ENDIAN */
-#ifndef BIG_ENDIAN
-#define BIG_ENDIAN __LITTLE_ENDIAN
-#endif /* BIG_ENDIAN */
-#endif /* BYTE_ORDER */
-
 #if !defined(MG_ARCH)
 #include "mongoose_custom.h"  // keep this include
 #endif
@@ -58,6 +43,9 @@
 #endif
 #endif  // !defined(MG_ARCH)
 
+// http://esr.ibiblio.org/?p=5095
+#define MG_BIG_ENDIAN (*(uint16_t *)"\0\xff" < 0x100)
+
 #include "arch_esp32.h"
 #include "arch_esp8266.h"
 #include "arch_freertos_lwip.h"
diff --git a/src/config.h b/src/config.h
index be4a7764..4a0d4967 100644
--- a/src/config.h
+++ b/src/config.h
@@ -45,7 +45,7 @@
 #endif
 
 #ifndef MG_ENABLE_MD5
-#define MG_ENABLE_MD5 0
+#define MG_ENABLE_MD5 1
 #endif
 
 // Set MG_ENABLE_WINSOCK=0 for Win32 builds with external IP stack (like LWIP)
diff --git a/src/md5.c b/src/md5.c
index b8203ca2..5d8dca26 100644
--- a/src/md5.c
+++ b/src/md5.c
@@ -1,21 +1,19 @@
-#include "md5.h"
 #include "arch.h"
+#include "md5.h"
 
 #if defined(MG_ENABLE_MD5) && MG_ENABLE_MD5
 
 static void mg_byte_reverse(unsigned char *buf, unsigned longs) {
-/* Forrest: MD5 expect LITTLE_ENDIAN, swap if BIG_ENDIAN */
-#if BYTE_ORDER == BIG_ENDIAN
-  do {
-    uint32_t t = (uint32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
-                 ((unsigned) buf[1] << 8 | buf[0]);
-    *(uint32_t *) buf = t;
-    buf += 4;
-  } while (--longs);
-#else
-  (void) buf;
-  (void) longs;
-#endif
+  if (MG_BIG_ENDIAN) {
+    do {
+      uint32_t t = (uint32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
+                   ((unsigned) buf[1] << 8 | buf[0]);
+      *(uint32_t *) buf = t;
+      buf += 4;
+    } while (--longs);
+  } else {
+    (void) buf, (void) longs;  // Little endian. Do nothing
+  }
 }
 
 #define F1(x, y, z) (z ^ (x & (y ^ z)))
diff --git a/src/sha1.c b/src/sha1.c
index fe974bc6..10be1c74 100644
--- a/src/sha1.c
+++ b/src/sha1.c
@@ -1,7 +1,7 @@
 /* Copyright(c) By Steve Reid <steve@edmweb.com> */
 /* 100% Public Domain */
-#include "sha1.h"
 #include "arch.h"
+#include "sha1.h"
 
 union char64long16 {
   unsigned char c[64];
@@ -11,11 +11,11 @@ union char64long16 {
 #define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
 
 static uint32_t blk0(union char64long16 *block, int i) {
-/* Forrest: SHA expect BIG_ENDIAN, swap if LITTLE_ENDIAN */
-#if BYTE_ORDER == LITTLE_ENDIAN
-  block->l[i] =
-      (rol(block->l[i], 24) & 0xFF00FF00) | (rol(block->l[i], 8) & 0x00FF00FF);
-#endif
+  if (MG_BIG_ENDIAN) {
+  } else {
+    block->l[i] = (rol(block->l[i], 24) & 0xFF00FF00) |
+                  (rol(block->l[i], 8) & 0x00FF00FF);
+  }
   return block->l[i];
 }
 
diff --git a/test/unit_test.c b/test/unit_test.c
index dc8341aa..be2e9303 100644
--- a/test/unit_test.c
+++ b/test/unit_test.c
@@ -777,9 +777,7 @@ static void test_http_server(void) {
   fetch(&mgr, buf, url, "GET /test/ HTTP/1.0\n\n");
   ASSERT(fetch(&mgr, buf, url, "GET /test/ HTTP/1.0\n\n") == 200);
   ASSERT(mg_strstr(mg_str(buf), mg_str(">Index of /test/<")) != NULL);
-#if BYTE_ORDER != BIG_ENDIAN
   ASSERT(mg_strstr(mg_str(buf), mg_str(">fuzz.c<")) != NULL);
-#endif
 
   {
     // Credentials
@@ -1730,9 +1728,7 @@ static void test_util(void) {
   ASSERT(mg_aton(mg_str("0.0.0.-1"), &a) == false);
   ASSERT(mg_aton(mg_str("127.0.0.1"), &a) == true);
   ASSERT(a.is_ip6 == false);
-#if BYTE_ORDER != BIG_ENDIAN
-  ASSERT(a.ip == 0x100007f);
-#endif
+  ASSERT(a.ip == mg_htonl(0x7f000001));
   ASSERT(strcmp(mg_ntoa(&a, buf, sizeof(buf)), "127.0.0.1") == 0);
 
   ASSERT(mg_aton(mg_str("1:2:3:4:5:6:7:8"), &a) == true);