diff --git a/com.oracle.truffle.r.engine/src/com/oracle/truffle/r/engine/TruffleRLanguageImpl.java b/com.oracle.truffle.r.engine/src/com/oracle/truffle/r/engine/TruffleRLanguageImpl.java
index f5e88edb17a05abf107da58aeada56d121db5845..79b5ec7640fd6c94afff6e6c916ddada9236641f 100644
--- a/com.oracle.truffle.r.engine/src/com/oracle/truffle/r/engine/TruffleRLanguageImpl.java
+++ b/com.oracle.truffle.r.engine/src/com/oracle/truffle/r/engine/TruffleRLanguageImpl.java
@@ -107,7 +107,7 @@ public final class TruffleRLanguageImpl extends TruffleRLanguage implements Scop
 
     @Override
     protected boolean isObjectOfLanguage(Object object) {
-        return false;
+        return object instanceof RTypedValue;
     }
 
     @Override
diff --git a/com.oracle.truffle.r.launcher/src/com/oracle/truffle/r/launcher/RMain.java b/com.oracle.truffle.r.engine/src/com/oracle/truffle/r/engine/shell/RMain.java
similarity index 93%
rename from com.oracle.truffle.r.launcher/src/com/oracle/truffle/r/launcher/RMain.java
rename to com.oracle.truffle.r.engine/src/com/oracle/truffle/r/engine/shell/RMain.java
index 347fafa2c36028c0771a3f28cf99ee6eee2a703c..10ebdf1654928f2c4d481e0e886375599d6c55c0 100644
--- a/com.oracle.truffle.r.launcher/src/com/oracle/truffle/r/launcher/RMain.java
+++ b/com.oracle.truffle.r.engine/src/com/oracle/truffle/r/engine/shell/RMain.java
@@ -20,7 +20,10 @@
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
-package com.oracle.truffle.r.launcher;
+package com.oracle.truffle.r.engine.shell;
+
+import com.oracle.truffle.r.launcher.RCommand;
+import com.oracle.truffle.r.launcher.RscriptCommand;
 
 /**
  * Convenience class that allows the R/Rscript entry to be chosen by an initial argument.
@@ -66,5 +69,4 @@ public class RMain {
         System.arraycopy(args, 1, nargs, 0, nargs.length);
         return nargs;
     }
-
 }