diff --git a/src/aig/dch/dchChoice.c b/src/aig/dch/dchChoice.c
index 09bbf2fb7..ee1ce034f 100644
--- a/src/aig/dch/dchChoice.c
+++ b/src/aig/dch/dchChoice.c
@@ -81,11 +81,18 @@ int Dch_DeriveChoiceCountEquivs( Aig_Man_t * pAig )
                 // remove referenced node from equivalence class
                 assert( pAig->pEquivs[pPrev->Id] == pTemp );
                 pAig->pEquivs[pPrev->Id] = pAig->pEquivs[pTemp->Id];
+                pAig->pEquivs[pTemp->Id] = NULL;
+                // how about the need to continue iterating over the list?
+                // pPrev = pTemp ???
                 Counter++;
             }
             nEquivs++;
         }
     }
+    printf( "Removed %d classes.\n", Counter );
+
+    if ( Counter )
+        Dch_DeriveChoiceCountEquivs( pAig );
 //    if ( Counter )
 //    printf( "Removed %d equiv nodes because of non-zero ref counter.\n", Counter );
     return nEquivs;
diff --git a/src/map/pcm/module.make b/src/map/pcm/module.make
new file mode 100644
index 000000000..e69de29bb
diff --git a/src/map/ply/module.make b/src/map/ply/module.make
new file mode 100644
index 000000000..e69de29bb