diff --git a/src/main/scala/leon/codegen/CompilationUnit.scala b/src/main/scala/leon/codegen/CompilationUnit.scala
index cd4a720a4be5f6347918e4d96179a53b8b380ee4..138cefc9cd5119df5f5855149428f7191c6a9960 100644
--- a/src/main/scala/leon/codegen/CompilationUnit.scala
+++ b/src/main/scala/leon/codegen/CompilationUnit.scala
@@ -240,6 +240,9 @@ class CompilationUnit(val ctx: LeonContext,
       }
       finiteMap(pairs.toSeq, from, to)
 
+    case (_, UnitType) =>
+      UnitLiteral()
+
     case _ =>
       throw CompilationException("Unsupported return value : " + e.getClass +" while expecting "+tpe)
   }