diff --git a/src/jsonselect.js b/src/jsonselect.js
index 2fbba51..6dd6e6c 100644
--- a/src/jsonselect.js
+++ b/src/jsonselect.js
@@ -148,7 +148,7 @@
             // (4) the 'x' value placeholder
             "(x)|" +
             // (5) binops
-            "(&&|\\|\\||[\\$\\^<>!\\*]=|[=+\\-*/%<>])|" +
+            "(&&|\\|\\||[\\$\\^<>!\\*\\-]=|[=+\\-*/%<>])|" +
             // (6) parens
             "([\\(\\)])" +
             ")"
@@ -166,6 +166,7 @@
         '$=': [ 5, function(lhs, rhs) { return is(lhs, 'string') && is(rhs, 'string') && lhs.lastIndexOf(rhs) === lhs.length - rhs.length; } ],
         '^=': [ 5, function(lhs, rhs) { return is(lhs, 'string') && is(rhs, 'string') && lhs.indexOf(rhs) === 0; } ],
         '*=': [ 5, function(lhs, rhs) { return is(lhs, 'string') && is(rhs, 'string') && lhs.indexOf(rhs) !== -1; } ],
+        '-=': [ 5, function(lhs, rhs) { return is(lhs, 'string') && is(rhs, 'string') && lhs.indexOf(rhs) === -1; } ],
         '>':  [ 5, function(lhs, rhs) { return is(lhs, 'number') && is(rhs, 'number') && lhs > rhs || is(lhs, 'string') && is(rhs, 'string') && lhs > rhs; } ],
         '<':  [ 5, function(lhs, rhs) { return is(lhs, 'number') && is(rhs, 'number') && lhs < rhs || is(lhs, 'string') && is(rhs, 'string') && lhs < rhs; } ],
         '=':  [ 3, function(lhs, rhs) { return lhs === rhs; } ],
@@ -435,7 +436,7 @@
     // THE EVALUATOR
 
     function isArray(o) {
-        return Array.isArray ? Array.isArray(o) : 
+        return Array.isArray ? Array.isArray(o) :
           toString.call(o) === "[object Array]";
     }