diff --git a/lib/json_logic/operation.rb b/lib/json_logic/operation.rb
index 93a9728..4127389 100644
--- a/lib/json_logic/operation.rb
+++ b/lib/json_logic/operation.rb
@@ -96,7 +96,10 @@ class Operation
       '%'     => ->(v, d) { v.map(&:to_i).reduce(:%) },
       '^'     => ->(v, d) { v.map(&:to_f).reduce(:**) },
       'merge' => ->(v, d) { v.flatten },
-      'in'    => ->(v, d) { interpolated_block(v[1], d).include? v[0] },
+      'in'    => ->(v, d)  do
+        result = interpolated_block(v[1], d)&.include? v[0]
+        result.nil? ? false : result
+      end,
       'cat'   => ->(v, d) { v.map(&:to_s).join },
       'log'   => ->(v, d) { puts v }
     }
diff --git a/test/json_logic_test.rb b/test/json_logic_test.rb
index 75a23b7..0b05582 100644
--- a/test/json_logic_test.rb
+++ b/test/json_logic_test.rb
@@ -142,4 +142,11 @@ def test_uses_data_missing
     assert_equal ["y"], JSONLogic.apply({ "missing": [vars] }, provided_data_missing_y)
     assert_equal ["x"], JSONLogic.apply({ "missing": [vars] }, provided_data_missing_x)
   end
+
+  def test_in_with_non_array
+    logic = { "in" => ["searchable_elem", { "var" => "non_array" }] }
+
+    refute JSONLogic.apply(logic, { "non_array" => nil })
+    refute JSONLogic.apply(logic, nil)
+  end
 end