diff --git a/src/crc.c b/src/crc.c
index 4309193..406b455 100644
--- a/src/crc.c
+++ b/src/crc.c
@@ -27,7 +27,7 @@ void CRCTable_Init() {
 	}
 }
 
-unsigned long CRC_BufferInternal(unsigned char *buffer, int len,
+unsigned long CRC_BufferInternal(unsigned char *buffer, unsigned long len,
 	unsigned long crc)
 {
 	unsigned char *p;
@@ -43,7 +43,7 @@ unsigned long CRC_BufferInternal(unsigned char *buffer, int len,
 	return (crc);
 }
 
-unsigned long CRC_Buffer(unsigned char *buffer, int len, unsigned long crc) {
+unsigned long CRC_Buffer(unsigned char *buffer, unsigned long len, unsigned long crc) {
 	CRCTable_Init();
 	return (CRC_BufferInternal(buffer, len, crc));
 }
@@ -57,11 +57,11 @@ unsigned long CRC_File(FILE *file) {
 	crc = 0xFFFFFFFFL;
 	for (;;) {
 		// Fill buffer
-		int count = fread(buffer, 1, 512, file);
+		size_t count = fread(buffer, 1, 512, file);
 		if (count == 0)
 			break;
 
-		crc = CRC_BufferInternal(buffer, count, crc);
+		crc = CRC_BufferInternal(buffer, (int)count, crc);
 	}
 	return (crc ^= 0xFFFFFFFFL);
 }
\ No newline at end of file
diff --git a/src/crc.h b/src/crc.h
index 5256b8d..bf1a2dc 100644
--- a/src/crc.h
+++ b/src/crc.h
@@ -3,7 +3,7 @@
 
 #include <stdio.h>
 
-unsigned long CRC_Buffer(unsigned char *buffer, int len, unsigned long crc);
+unsigned long CRC_Buffer(unsigned char *buffer, unsigned long len, unsigned long crc);
 unsigned long CRC_File(FILE *file);
 
 #endif
diff --git a/src/fileutil.c b/src/fileutil.c
index 8441e26..01c9637 100644
--- a/src/fileutil.c
+++ b/src/fileutil.c
@@ -129,6 +129,7 @@ void FileTime_Print(FileTime fileTime) {
 }
 
 #ifdef WIN32
+
 long long File_GetSize(char *fileName) {
 	HANDLE hFile;
 	DWORD fSize;
@@ -139,6 +140,7 @@ long long File_GetSize(char *fileName) {
 	return (fSize);
 }
 #else
+
 long long File_GetSize(char *fileName) {
 	struct stat fs;
 	lstat(fileName, &fs);
@@ -169,7 +171,7 @@ void File_GetSizeAndTime(char *fileName, long long *size, FileTime *time) {
 #endif
 
 void File_GetName(char *path, char *name) {
-	int i, j;
+	size_t i, j;
 
 	i = strlen(path) - 1;
 	while (i >= 0) {
@@ -276,7 +278,7 @@ int File_MakeDirectory(char *path) {
 
 void File_IterateDir(char *path,
 	int(*func)(char *path, char *name, void *data), void *data) {
-	int handle;
+	intptr_t handle;
 	struct _finddata_t fileinfo;
 	char f_path[MaxPath];
 	int fin = 0;
@@ -352,8 +354,8 @@ int File_Copy(const char *pathOrig, const char *pathDest) {
 	FILE *fOrig = NULL;
 	FILE *fDest = NULL;
 	char *buffer = NULL;
-	int readLen = 0;
-	int writeLen = 0;
+	size_t readLen = 0;
+	size_t writeLen = 0;
 	int status = 0;
 
 	if ((fOrig = fopen(pathOrig, "rb")) == NULL) {
diff --git a/src/util.c b/src/util.c
index 6e6fb26..0c6df3c 100644
--- a/src/util.c
+++ b/src/util.c
@@ -11,7 +11,7 @@
 // Copies a string.
 char *String_Copy(char *str) {
 	char *strnew;
-	int len;
+	size_t len;
 	len = strlen(str);
 	strnew = malloc(len + 1);
 	if (strnew != NULL) {