diff --git a/src/inmanta/ast/constraint/expression.py b/src/inmanta/ast/constraint/expression.py
index 2232ef8a62..acdba3ad5e 100644
--- a/src/inmanta/ast/constraint/expression.py
+++ b/src/inmanta/ast/constraint/expression.py
@@ -437,7 +437,7 @@ def _is_final(self, result):
 
 class In(BinaryOperator):
     """
-        The in operator for iterable types
+        The in operator for iterable types and dicts
     """
     __op = "in"
 
@@ -448,11 +448,13 @@ def _bin_op(self, arg1, arg2):
         """
             @see Operator#_op
         """
-        if not (isinstance(arg2, list) or (hasattr(arg2, "type") and arg2.type() == list)):
-            raise Exception("Operand two of 'in' can only be a list (%s)" % arg2[0])
-
-        for arg in arg2:
-            if arg == arg1:
-                return True
+        if isinstance(arg2, dict):
+            return arg1 in arg2
+        elif isinstance(arg2, list):
+            for arg in arg2:
+                if arg == arg1:
+                    return True
+        else:
+            raise Exception("Operand two of 'in' can only be a list or dict (%s)" % arg2[0])
 
         return False
diff --git a/tests/test_compilation.py b/tests/test_compilation.py
index 20249e4ec5..d504c4b7f9 100644
--- a/tests/test_compilation.py
+++ b/tests/test_compilation.py
@@ -2272,3 +2272,37 @@ def test_lnr_on_double_is_defined(snippetcompiler):
 a.one = a
 """)
     compiler.do_compile()
+
+
+def test_673_in_dict(snippetcompiler):
+    snippetcompiler.setup_for_snippet("""
+entity Test:
+    dict attributes
+end
+
+implementation test for Test:
+
+end
+
+implement Test using test when "foo" in self.attributes
+
+Test(attributes={"foo": 42})
+""")
+    compiler.do_compile()
+
+
+def test_673_in_list(snippetcompiler):
+    snippetcompiler.setup_for_snippet("""
+entity Test:
+    string[] attributes
+end
+
+implementation test for Test:
+
+end
+
+implement Test using test when "foo" in self.attributes
+
+Test(attributes=["blah", "foo"])
+""")
+    compiler.do_compile()