diff --git a/spec/imbecile_spec.rb b/spec/imbecile_spec.rb
index c34fc9d..645daac 100644
--- a/spec/imbecile_spec.rb
+++ b/spec/imbecile_spec.rb
@@ -1,20 +1,25 @@
 require "fileutils"
 
-def write_grammar(grammar)
-  File.write("spec/run/testparser.i", grammar)
-end
-
-def build_parser
-  result = system(*%w[./imbecile.sh spec/run/testparser.i spec/run/testparser.d])
-  expect(result).to be_truthy
-end
-
-def compile(test_file)
-  result = system(*%w[gdc -o spec/run/testparser spec/run/testparser.d], test_file)
-  expect(result).to be_truthy
-end
-
 describe Imbecile do
+  def write_grammar(grammar)
+    File.write("spec/run/testparser.i", grammar)
+  end
+
+  def build_parser
+    result = system(*%w[./imbecile.sh spec/run/testparser.i spec/run/testparser.d])
+    expect(result).to be_truthy
+  end
+
+  def compile(test_file)
+    result = system(*%w[gdc -funittest -o spec/run/testparser spec/run/testparser.d], test_file)
+    expect(result).to be_truthy
+  end
+
+  def run
+    result = system("spec/run/testparser")
+    expect(result).to be_truthy
+  end
+
   before(:each) do
     FileUtils.rm_rf("spec/run")
     FileUtils.mkdir_p("spec/run")
@@ -31,5 +36,6 @@ rule Start [] <<
 EOF
     build_parser
     compile("spec/test_d_lexer.d")
+    run
   end
 end
diff --git a/spec/test_d_lexer.d b/spec/test_d_lexer.d
index 905869d..a2bb5ee 100644
--- a/spec/test_d_lexer.d
+++ b/spec/test_d_lexer.d
@@ -2,3 +2,8 @@ int main()
 {
     return 0;
 }
+
+unittest
+{
+    assert(true);
+}