diff --git a/iface/nips/Makefile.am b/iface/nips/Makefile.am
index c8db9eca1..1d474c2f4 100644
--- a/iface/nips/Makefile.am
+++ b/iface/nips/Makefile.am
@@ -35,7 +35,7 @@ libspotnips_la_SOURCES = \
   nips.cc
 
 noinst_PROGRAMS = \
-  dottynips
+  dottynips empt_check
 
 dottynips_SOURCES = dottynips.cc
 dottynips_LDADD = libspotnips.la $(builddir)/nips_vm/libnipsvm.la
diff --git a/iface/nips/nips.cc b/iface/nips/nips.cc
index a156f121b..d7f0cbc0b 100644
--- a/iface/nips/nips.cc
+++ b/iface/nips/nips.cc
@@ -22,6 +22,7 @@
 #include <cassert>
 #include "misc/hashfunc.hh"
 #include "nips.hh"
+#include "nipsvm.h"
 
 namespace spot
 {
@@ -385,7 +386,8 @@ namespace spot
     if (bytecode_ == 0)
       throw nips_exception("bytecode_load_from_file()");
 
-    int res = nipsvm_init(&nipsvm_, bytecode_, successor_state_callback,
+    nipsvm_ = new nipsvm_t();
+    int res = nipsvm_init(nipsvm_, bytecode_, successor_state_callback,
 			  search_error_callback);
 
     if (res != 0)
@@ -394,12 +396,21 @@ namespace spot
 
   nips_interface::~nips_interface()
   {
-    nipsvm_finalize(&nipsvm_);
+    nipsvm_finalize(nipsvm_);
     bytecode_unload(bytecode_);
+    delete nipsvm_;
+  }
+
+  bool nips_interface::has_monitor() const
+  {
+    if (bytecode_ == 0)
+      throw nips_exception("The bytecode isn't loaded");
+
+    return bytecode_monitor_present(bytecode_);
   }
 
   tgba* nips_interface::automaton()
   {
-    return new tgba_nips(dict_, &nipsvm_);
+    return new tgba_nips(dict_, nipsvm_);
   }
 }
diff --git a/iface/nips/nips.hh b/iface/nips/nips.hh
index 988a887a9..eff4ebec9 100644
--- a/iface/nips/nips.hh
+++ b/iface/nips/nips.hh
@@ -30,9 +30,10 @@
 # include "tgba/tgba.hh"
 # include "common.hh"
 
-// Damn, nipsvm.h is include, to fix.
-# include "nipsvm.h"
 
+// Fwd declarations.
+typedef struct nipsvm_t nipsvm_t;
+typedef struct t_bytecode nipsvm_bytecode_t;
 
 namespace spot
 {
@@ -54,10 +55,11 @@ namespace spot
   public:
     nips_interface(bdd_dict* dict, const std::string& filename);
     ~nips_interface();
+    bool has_monitor() const;
     tgba* automaton();
   private:
     bdd_dict* dict_;
-    nipsvm_t nipsvm_;
+    nipsvm_t* nipsvm_;
     nipsvm_bytecode_t* bytecode_;
   };
 }