diff --git a/src/osal.h b/src/osal.h
index 3819fa4a..162060c4 100644
--- a/src/osal.h
+++ b/src/osal.h
@@ -202,45 +202,70 @@ typedef pthread_mutex_t mdbx_fastmutex_t;
 #if !defined(__BYTE_ORDER__) || !defined(__ORDER_LITTLE_ENDIAN__) ||           \
     !defined(__ORDER_BIG_ENDIAN__)
 
-#if defined(HAVE_ENDIAN_H)
+/* *INDENT-OFF* */
+/* clang-format off */
+#if defined(__GLIBC__) || defined(__GNU_LIBRARY__) || defined(__ANDROID__) ||  \
+    defined(HAVE_ENDIAN_H) || __has_include(<endian.h>)
 #include <endian.h>
-#elif defined(HAVE_SYS_PARAM_H)
-#include <sys/param.h> /* for endianness */
-#elif defined(HAVE_NETINET_IN_H) && defined(HAVE_RESOLV_H)
-#include <netinet/in.h>
-#include <resolv.h> /* defines BYTE_ORDER on HPUX and Solaris */
-#endif
+#elif defined(__APPLE__) || defined(__MACH__) || defined(__OpenBSD__) ||       \
+    defined(HAVE_MACHINE_ENDIAN_H) || __has_include(<machine/endian.h>)
+#include <machine/endian.h>
+#elif defined(HAVE_SYS_ISA_DEFS_H) || __has_include(<sys/isa_defs.h>)
+#include <sys/isa_defs.h>
+#elif (defined(HAVE_SYS_TYPES_H) && defined(HAVE_SYS_ENDIAN_H)) ||             \
+    (__has_include(<sys/types.h>) && __has_include(<sys/endian.h>))
+#include <sys/endian.h>
+#include <sys/types.h>
+#elif defined(__bsdi__) || defined(__DragonFly__) || defined(__FreeBSD__) ||   \
+    defined(__NETBSD__) || defined(__NetBSD__) ||                              \
+    defined(HAVE_SYS_PARAM_H) || __has_include(<sys/param.h>)
+#include <sys/param.h>
+#endif /* OS */
+/* *INDENT-ON* */
+/* clang-format on */
 
 #if defined(__BYTE_ORDER) && defined(__LITTLE_ENDIAN) && defined(__BIG_ENDIAN)
 #define __ORDER_LITTLE_ENDIAN__ __LITTLE_ENDIAN
 #define __ORDER_BIG_ENDIAN__ __BIG_ENDIAN
 #define __BYTE_ORDER__ __BYTE_ORDER
+#elif defined(_BYTE_ORDER) && defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN)
+#define __ORDER_LITTLE_ENDIAN__ _LITTLE_ENDIAN
+#define __ORDER_BIG_ENDIAN__ _BIG_ENDIAN
+#define __BYTE_ORDER__ _BYTE_ORDER
 #else
 #define __ORDER_LITTLE_ENDIAN__ 1234
 #define __ORDER_BIG_ENDIAN__ 4321
-#if defined(__LITTLE_ENDIAN__) || defined(_LITTLE_ENDIAN) ||                   \
+
+#if defined(__LITTLE_ENDIAN__) ||                                              \
+    (defined(_LITTLE_ENDIAN) && !defined(_BIG_ENDIAN)) ||                      \
     defined(__ARMEL__) || defined(__THUMBEL__) || defined(__AARCH64EL__) ||    \
     defined(__MIPSEL__) || defined(_MIPSEL) || defined(__MIPSEL) ||            \
-    defined(__i386) || defined(__x86_64__) || defined(_M_IX86) ||              \
-    defined(_M_X64) || defined(i386) || defined(_X86_) || defined(__i386__) || \
-    defined(_X86_64_) || defined(_M_ARM) || defined(_M_ARM64) ||               \
-    defined(__e2k__)
+    defined(_M_ARM) || defined(_M_ARM64) || defined(__e2k__) ||                \
+    defined(__elbrus_4c__) || defined(__elbrus_8c__) || defined(__bfin__) ||   \
+    defined(__BFIN__) || defined(__ia64__) || defined(_IA64) ||                \
+    defined(__IA64__) || defined(__ia64) || defined(_M_IA64) ||                \
+    defined(__itanium__) || defined(__ia32__) || defined(__CYGWIN__) ||        \
+    defined(_WIN64) || defined(_WIN32) || defined(__TOS_WIN__) ||              \
+    defined(__WINDOWS__)
 #define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
-#elif defined(__BIG_ENDIAN__) || defined(_BIG_ENDIAN) || defined(__ARMEB__) || \
-    defined(__THUMBEB__) || defined(__AARCH64EB__) || defined(__MIPSEB__) ||   \
-    defined(_MIPSEB) || defined(__MIPSEB) || defined(_M_IA64)
+
+#elif defined(__BIG_ENDIAN__) ||                                               \
+    (defined(_BIG_ENDIAN) && !defined(_LITTLE_ENDIAN)) ||                      \
+    defined(__ARMEB__) || defined(__THUMBEB__) || defined(__AARCH64EB__) ||    \
+    defined(__MIPSEB__) || defined(_MIPSEB) || defined(__MIPSEB) ||            \
+    defined(__m68k__) || defined(M68000) || defined(__hppa__) ||               \
+    defined(__hppa) || defined(__HPPA__) || defined(__sparc__) ||              \
+    defined(__sparc) || defined(__370__) || defined(__THW_370__) ||            \
+    defined(__s390__) || defined(__s390x__) || defined(__SYSC_ZARCH__)
 #define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__
+
 #else
 #error __BYTE_ORDER__ should be defined.
-#endif
+#endif /* Arch */
+
 #endif
 #endif /* __BYTE_ORDER__ || __ORDER_LITTLE_ENDIAN__ || __ORDER_BIG_ENDIAN__ */
 
-#if __BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__ &&                               \
-    __BYTE_ORDER__ != __ORDER_BIG_ENDIAN__
-#error Unsupported byte order.
-#endif
-
 /*----------------------------------------------------------------------------*/
 /* Memory/Compiler barriers, cache coherence */