diff --git a/osscan.cc b/osscan.cc
index 241ad17d8..05555101a 100644
--- a/osscan.cc
+++ b/osscan.cc
@@ -371,7 +371,7 @@ bool expr_match(const char *val, size_t vlen, const char *expr, size_t explen, b
         }
         goto next_expr;
       } else {
-        q1 = strchr_p(p, p_end, '-');
+        q1 = strchr_p(p, q ? q : p_end, '-');
         if (q1 != NULL) {
           size_t sublen1 = q1 - p;
           if ((vlen > sublen1)
diff --git a/tests/expr_match_test.cc b/tests/expr_match_test.cc
index 53e2d8d0d..2cc11d549 100644
--- a/tests/expr_match_test.cc
+++ b/tests/expr_match_test.cc
@@ -152,6 +152,7 @@ const struct expr_test tests[] = {
   {"M[500|5B4]ST11NW[7-9]", "M5B4ST11NW79", false},
   {"M[500|5B4]ST11NW[7-9]", "M500ST11NWA", false},
   {"M[500|5B4]ST11NW[7-9]", "M5B40ST11NW9", false},
+  {"A|20-22", "A", true},
   {"", "", true}
 };