Index: generic/nsf.c
===================================================================
diff -u -N -rbec5f06e14cc409243e1e59e6c51c91bace39a28 -rb3e820b47ce81dc7184f7387818353ad2018a22f
--- generic/nsf.c	(.../nsf.c)	(revision bec5f06e14cc409243e1e59e6c51c91bace39a28)
+++ generic/nsf.c	(.../nsf.c)	(revision b3e820b47ce81dc7184f7387818353ad2018a22f)
@@ -13040,7 +13040,7 @@
         memcpy(buffer, "substdefault", (size_t)len);
 
         if ((paramsPtr->flags & NSF_ARG_SUBST_DEFAULT_ALL) != 0u) {
-          memcpy(buffer + len + 1, "=0b", (size_t)len);
+          memcpy(buffer + len + 1, "=0b", 3);
           len += 4;
           buffer[len] = ((paramsPtr->flags & NSF_ARG_SUBST_DEFAULT_VARIABLES) != 0u) ? '1' : '0';
           len ++;