diff --git a/business_rules/operators.py b/business_rules/operators.py
index d43e5b1f..55d982a9 100644
--- a/business_rules/operators.py
+++ b/business_rules/operators.py
@@ -95,6 +95,10 @@ def matches_regex(self, regex):
     def non_empty(self):
         return bool(self.value)
 
+    @type_operator(FIELD_TEXT)
+    def is_in(self, other_string):
+        return self.value in other_string
+
 
 @export_type
 class NumericType(BaseType):
diff --git a/tests/test_operators.py b/tests/test_operators.py
index 824d4a69..0d51896c 100644
--- a/tests/test_operators.py
+++ b/tests/test_operators.py
@@ -46,6 +46,9 @@ def test_non_empty(self):
         self.assertFalse(StringType("").non_empty())
         self.assertFalse(StringType(None).non_empty())
 
+    def test_string_is_in(self):
+        self.assertTrue(StringType("hello").is_in("hello world"))
+        self.assertFalse(StringType("word").is_in("hello world"))
 
 class NumericOperatorTests(TestCase):