diff --git a/samples/lambdacalc/build.xml b/samples/lambdacalc/build.xml
index 0ad2ba52..5cbe1f33 100644
--- a/samples/lambdacalc/build.xml
+++ b/samples/lambdacalc/build.xml
@@ -175,6 +175,7 @@
           <module ref="af858d84-85f2-42f4-a854-0b3c6b5cd482(samples.lambdacalc)" kind="cl" />
         </dependencies>
         <uses>
+          <language id="l:f2801650-65d5-424e-bb1b-463a8781b786:jetbrains.mps.baseLanguage.javadoc" />
           <language id="l:f61473f9-130f-42f6-b98d-6c438812c2f6:jetbrains.mps.baseLanguage.unitTest" />
           <language id="l:63650c59-16c8-498a-99c8-005c7ee9515d:jetbrains.mps.lang.access" />
           <language id="l:3a13115c-633c-4c5c-bbcc-75c4219e9555:jetbrains.mps.lang.quotation" />