diff --git a/backends/smt2/smtbmc.py b/backends/smt2/smtbmc.py
index eac693632..0cfb386a1 100644
--- a/backends/smt2/smtbmc.py
+++ b/backends/smt2/smtbmc.py
@@ -249,7 +249,7 @@ def get_constr_expr(db, state, final=False, getvalues=False):
         if state not in db:
             return ([], [], []) if getvalues else "true"
 
-    netref_regex = re.compile(r'(^|[( ])\[(-?[0-9]+:|)([^\]]+)\](?=[ )]|$)')
+    netref_regex = re.compile(r'(^|[( ])\[(-?[0-9]+:|)([^\]]*)\](?=[ )]|$)')
 
     def replace_netref(match):
         state_sel = match.group(2)
diff --git a/backends/smt2/smtio.py b/backends/smt2/smtio.py
index eccb65014..72bd8b178 100644
--- a/backends/smt2/smtio.py
+++ b/backends/smt2/smtio.py
@@ -534,6 +534,8 @@ class SmtIo:
     def net_expr(self, mod, base, path):
         if len(path) == 1:
             assert mod in self.modinfo
+            if path[0] == "":
+                return base
             if path[0] in self.modinfo[mod].cells:
                 return "(|%s_h %s| %s)" % (mod, path[0], base)
             if path[0] in self.modinfo[mod].wsize: