diff --git a/scripts/smt2-bmc/async.py b/scripts/smt2-bmc/async.py
index c60cf15..e4854de 100644
--- a/scripts/smt2-bmc/async.py
+++ b/scripts/smt2-bmc/async.py
@@ -22,7 +22,7 @@ python3 async.py [options]
     sys.exit(1)
 
 try:
-    opts, args = getopt.getopt(sys.argv[1:], "s:t:vdp")
+    opts, args = getopt.getopt(sys.argv[1:], so.optstr + "t:")
 except:
     usage()
 
diff --git a/scripts/smt2-bmc/smtio.py b/scripts/smt2-bmc/smtio.py
index e223e85..df14dee 100644
--- a/scripts/smt2-bmc/smtio.py
+++ b/scripts/smt2-bmc/smtio.py
@@ -219,6 +219,7 @@ class smtio:
 
 class smtopts:
     def __init__(self):
+        self.optstr = "s:d:vp"
         self.solver = "yices"
         self.debug_print = False
         self.debug_file = None
diff --git a/scripts/smt2-bmc/sync.py b/scripts/smt2-bmc/sync.py
index eca0371..23cadc6 100644
--- a/scripts/smt2-bmc/sync.py
+++ b/scripts/smt2-bmc/sync.py
@@ -18,7 +18,7 @@ python3 sync.py [options]
     sys.exit(1)
 
 try:
-    opts, args = getopt.getopt(sys.argv[1:], "s:t:vdp")
+    opts, args = getopt.getopt(sys.argv[1:], so.optstr + "t:")
 except:
     usage()