diff --git a/test/unit/lexer_unit_test.rb b/test/unit/lexer_unit_test.rb
index 26a25b62..45cfc53e 100644
--- a/test/unit/lexer_unit_test.rb
+++ b/test/unit/lexer_unit_test.rb
@@ -136,4 +136,11 @@ class LexerUnitTest < Minitest::Test
   def tokenize(input)
     Lexer.new(input).tokenize
   end
+
+  def test_tokenize_incomplete_expression
+    assert_equal([[:id, "false"], [:dash, "-"], [:end_of_string]], Lexer.new("false -").tokenize)
+    assert_equal([[:id, "false"], [:comparison, "<"], [:end_of_string]], Lexer.new("false <").tokenize)
+    assert_equal([[:id, "false"], [:comparison, ">"], [:end_of_string]], Lexer.new("false >").tokenize)
+    assert_equal([[:id, "false"], [:number, "1"], [:end_of_string]], Lexer.new("false 1").tokenize)
+  end
 end