1 files changed, 1 insertions, 1 deletions

diff --git a/psi/interp.c b/psi/interp.c
index 68f977c56..3ac5c70cf 100644
--- a/psi/interp.c
+++ b/psi/interp.c
@@ -707,7 +707,7 @@ again:
                  * i.e. it's an internal operator we have hidden
                  */
                 code = dict_find_string(systemdict, (const char *)bufptr, &tobj);
-                if (code < 0) {
+                if (code <= 0) {
                     buf[0] = buf[1] = buf[rlen + 2] = buf[rlen + 3] = '-';
                     rlen += 4;
                     bufptr = buf;