diff --git a/mypyc/doc/str_operations.rst b/mypyc/doc/str_operations.rst
index b2e632a8bbb6..a7e9ccc58cd1 100644
--- a/mypyc/doc/str_operations.rst
+++ b/mypyc/doc/str_operations.rst
@@ -21,6 +21,7 @@ Operators
 * Slicing (``s[n:m]``, ``s[n:]``, ``s[:m]``)
 * Comparisons (``==``, ``!=``)
 * Augmented assignment (``s1 += s2``)
+* Containment (``s1 in s2``)
 
 .. _str-methods:
 
diff --git a/mypyc/primitives/str_ops.py b/mypyc/primitives/str_ops.py
index 255728187604..aef3575d8eb4 100644
--- a/mypyc/primitives/str_ops.py
+++ b/mypyc/primitives/str_ops.py
@@ -84,6 +84,17 @@
     error_kind=ERR_MAGIC,
 )
 
+# item in str
+binary_op(
+    name="in",
+    arg_types=[str_rprimitive, str_rprimitive],
+    return_type=c_int_rprimitive,
+    c_function_name="PyUnicode_Contains",
+    error_kind=ERR_NEG_INT,
+    truncated_type=bool_rprimitive,
+    ordering=[1, 0],
+)
+
 # str.join(obj)
 method_op(
     name="join",
diff --git a/mypyc/test-data/run-strings.test b/mypyc/test-data/run-strings.test
index 94fcf84f085b..7eadaeee0707 100644
--- a/mypyc/test-data/run-strings.test
+++ b/mypyc/test-data/run-strings.test
@@ -140,11 +140,24 @@ def test_partition() -> None:
     with assertRaises(ValueError, "empty separator"):
         rpartition(s_partition, "")
 
+def contains(s: str, o: str) -> bool:
+    return o in s
+
 def getitem(s: str, index: int) -> str:
     return s[index]
 
 s = "abc"
 
+def test_contains() -> None:
+    assert contains(s, "a") is True
+    assert contains(s, "abc") is True
+    assert contains(s, "Hello") is False
+    assert contains(s, "bc") is True
+    assert contains(s, "abcd") is False
+    assert contains(s, "bb") is False
+    assert contains(s, "") is True
+    assert contains(s, " ") is False
+
 def test_getitem() -> None:
     assert getitem(s, 0) == "a"
     assert getitem(s, 1) == "b"