diff --git a/src/internal/ntapi_log.h b/src/internal/ntapi_log.h
index 108bc18..ae9cce9 100644
--- a/src/internal/ntapi_log.h
+++ b/src/internal/ntapi_log.h
@@ -32,7 +32,7 @@ static inline ssize_t __ntapi_log_write(void * msg,uint32_t size)
 	void *		hlog;
 	nt_iosb		iosb;
 	uintptr_t	buffer[8] = {0};
-	char *		ch = (char *)buffer;
+	unsigned char *	ch = (unsigned char *)buffer;
 
 	if (!(hlog = __ntapi_internals()->rtdata->hlog))
 		return NT_STATUS_INVALID_HANDLE;
@@ -52,7 +52,7 @@ static inline ssize_t __ntapi_log_write(void * msg,uint32_t size)
 		hlog,
 		0,0,0,&iosb,
 		buffer,
-		(uint32_t)(ch-(char *)buffer),
+		(uint32_t)(ch-(unsigned char *)buffer),
 		0,0);
 
 	status = __ntapi->zw_write_file(