diff --git a/c-programming/io/fwrite_le.c b/c-programming/io/fwrite_le.c
index c40667e..f21120a 100644
--- a/c-programming/io/fwrite_le.c
+++ b/c-programming/io/fwrite_le.c
@@ -8,19 +8,11 @@
 #include "fwrite_le.h"
 
 int detect_endianness(void) {
-	volatile uint32_t i = 0x01234567;
-	uint8_t* bytes = (uint8_t*)(&i);
-	if (bytes[0] == 0x01 &&
-	    bytes[1] == 0x23 &&
-	    bytes[2] == 0x45 &&
-	    bytes[3] == 0x67)
-		return DETECTED_BIG_ENDIAN;
-	else if (
-	    bytes[0] == 0x67 &&
-	    bytes[1] == 0x45 &&
-	    bytes[2] == 0x23 &&
-	    bytes[3] == 0x01)
-		return DETECTED_LITTLE_ENDIAN;
+	volatile uint32_t native_order_value = ORDER_NATIVE_U32;
+	uint8_t* as_bytes = (uint8_t*)&native_order_value;
+
+	ifeq_b32_ret(as_bytes, ORDER_LITTLE_ENDIAN_S4, DETECTED_LITTLE_ENDIAN);
+	ifeq_b32_ret(as_bytes, ORDER_BIG_ENDIAN_S4,    DETECTED_BIG_ENDIAN   );
 	return UNSUPPORTED_ENDIANNESS;
 }
 
@@ -31,6 +23,11 @@ void reorder_le_be(
 	uint8_t* bytes,
 #endif
 	size_t count, size_t step) {
+
+	if (step == 1) {
+		return;
+	}
+
 	for (size_t i = 0; i < count; i += step) {
 		const size_t div_size = step / 2;
 		for (size_t j = 0; j < div_size; j++) {
@@ -47,7 +44,11 @@ void reorder_le_be(
 	}
 }
 
-size_t fwrite_le(void* ptr, size_t size, size_t count, FILE* stream) {
+size_t fwrite_le(
+#if FWRITE_LE_NO_MODIFICATION
+	const
+#endif
+	void* ptr, size_t size, size_t count, FILE* stream) {
 	/*
 	 * warning: this function modifies `void* ptr` by default!
 	 *          (if FWRITE_LE_NO_MODIFICATION in the header is 0)
@@ -56,11 +57,12 @@ size_t fwrite_le(void* ptr, size_t size, size_t count, FILE* stream) {
 		return 0;
 
 	int endianness = detect_endianness();
-	if (endianness == UNSUPPORTED_ENDIANNESS) {
+	if (size == 1 || endianness == DETECTED_LITTLE_ENDIAN)
+		return fwrite(ptr, size, count, stream);
+	else if (endianness == UNSUPPORTED_ENDIANNESS) {
 		fprintf(stderr, "Unsupported endianness\n");
 		exit(EXIT_FAILURE);
-	} else if (endianness == DETECTED_LITTLE_ENDIAN)
-		return fwrite(ptr, size, count, stream);
+	}
 
 	// case: big-endian
 	size_t bytes_count = size * count;
diff --git a/c-programming/io/fwrite_le.h b/c-programming/io/fwrite_le.h
index dfb4524..da215aa 100644
--- a/c-programming/io/fwrite_le.h
+++ b/c-programming/io/fwrite_le.h
@@ -5,22 +5,31 @@
  * License: Unlicense
  */
 
+#ifndef _FWRITE_LE_H
+#define _FWRITE_LE_H
+
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
-#ifndef _FWRITE_LE_H
-#define _FWRITE_LE_H
-
 #define FWRITE_LE_NO_MODIFICATION 0
 
 #define DETECTED_LITTLE_ENDIAN 0
 #define DETECTED_BIG_ENDIAN 1
 #define UNSUPPORTED_ENDIANNESS -1
 
+#define ORDER_NATIVE_U32 0x01234567
+#define ORDER_LITTLE_ENDIAN_S4 "\x67\x45\x23\x01"
+#define ORDER_BIG_ENDIAN_S4 "\x01\x23\x45\x67"
+#define ifeq_b32_ret(lhs, rhs, value) if (!memcmp(lhs, rhs, 4)) return value;
+
 int detect_endianness(void);
-size_t fwrite_le(void* ptr, size_t size, size_t count, FILE* stream);
+size_t fwrite_le(
+#if FWRITE_LE_NO_MODIFICATION
+	const
+#endif
+	void* ptr, size_t size, size_t count, FILE* stream);
 void reorder_le_be(
 #if FWRITE_LE_NO_MODIFICATION
 	uint8_t* dest, uint8_t* src,