diff --git a/src/base/system.c b/src/base/system.c
index 47893aa3d..457b761a9 100644
--- a/src/base/system.c
+++ b/src/base/system.c
@@ -262,7 +262,23 @@ int mem_check_imp()
 IOHANDLE io_open(const char *filename, int flags)
 {
 	if(flags == IOFLAG_READ)
+	{
+	#if defined(CONF_FAMILY_WINDOWS)
+		// check for filename case sensitive
+		WIN32_FIND_DATA finddata;
+		HANDLE handle;
+		int length;
+		
+		length = str_length(filename);
+		if(!filename || !length || filename[length-1] == '\\')
+			return 0x0;
+		handle = FindFirstFile(filename, &finddata);
+		if(handle == INVALID_HANDLE_VALUE || str_comp(filename+length-str_length(finddata.cFileName), finddata.cFileName))
+			return 0x0;
+		FindClose(handle);
+	#endif
 		return (IOHANDLE)fopen(filename, "rb");
+	}
 	if(flags == IOFLAG_WRITE)
 		return (IOHANDLE)fopen(filename, "wb");
 	return 0x0;