diff --git a/native/SunOS.cpp b/native/SunOS.cpp
index 83a498b..3c0802c 100644
--- a/native/SunOS.cpp
+++ b/native/SunOS.cpp
@@ -203,9 +203,11 @@ namespace native {
 
 
 	int open_resource_fork(const std::string &path_name, int oflag) {
-
-		// should create if it doesn't exist...
-		if ((oflag & O_ACCMODE) & O_WRONLY) oflag |= O_CREAT;
+		/* under HFS, every file has a resource fork.
+		 * Therefore, create it if opening for O_RDWR or O_WRONLY
+		 */
+		int mode = oflag & O_ACCMODE;
+		if (mode == O_WRONLY || mode == O_RDWR) oflag |= O_CREAT;
 		return attropen(path_name.c_str(), XATTR_RESOURCEFORK_NAME, oflag, 0666);
 	}