--- a/crc32.c
+++ b/crc32.c
@@ -1,10 +1,12 @@
+#include <stdint.h>
+
 unsigned long crcval;
 unsigned long crctable[256];
 
-unsigned long crc_reflect(unsigned long x, int bits)
-{
-	int i;
-	unsigned long v = 0, b = 1 << (bits - 1);
+unsigned long crc_reflect(uint32_t x, int bits)
+{
+	uint32_t i;
+	uint32_t v = 0, b = 1 << (bits - 1);
 
 	for (i = 0; i < bits; i++)
 	{
@@ -16,8 +18,8 @@
 
 void crc_init(void)
 {
-	unsigned long crcpol = 0x04c11db7;
-	unsigned long i, j, k;
+	uint32_t crcpol = 0x04c11db7;
+	uint32_t i, j, k;
 
 	for (i = 0; i < 256; i++)
 	{