diff -uNr socat-1.7.3.2/xio-gopen.c socat-1.7.3.2.mod/xio-gopen.c
--- socat-1.7.3.2/xio-gopen.c	2017-01-06 23:51:24.000000000 +0200
+++ socat-1.7.3.2.mod/xio-gopen.c	2018-12-31 14:22:34.046949870 +0200
@@ -33,12 +33,7 @@
    }
    st_mode = result;
 
-   if (exists) {
-      /* file (or at least named entry) exists */
-      if ((xioflags&XIO_ACCMODE) != XIO_RDONLY) {
-	 openflags |= O_APPEND;
-      }
-   } else {
+   if (!exists) {
       openflags |= O_CREAT;
    }