diff --git a/amgprec/impl/aggregator/MatchBoxPC.cpp b/amgprec/impl/aggregator/MatchBoxPC.cpp
index 90b448dc..eb56adce 100644
--- a/amgprec/impl/aggregator/MatchBoxPC.cpp
+++ b/amgprec/impl/aggregator/MatchBoxPC.cpp
@@ -42,7 +42,6 @@
 #include <stdlib.h>
 #if !defined(SERIAL_MPI)
 #include <mpi.h>
-#endif
 
 #include "MatchBoxPC.h"
 #ifdef __cplusplus
@@ -127,3 +126,4 @@ void sMatchBoxPC(MilanLongInt NLVer, MilanLongInt NLEdge,
 #ifdef __cplusplus
 }
 #endif
+#endif
diff --git a/amgprec/impl/aggregator/MatchBoxPC.h b/amgprec/impl/aggregator/MatchBoxPC.h
index a1fddb59..67486f2d 100644
--- a/amgprec/impl/aggregator/MatchBoxPC.h
+++ b/amgprec/impl/aggregator/MatchBoxPC.h
@@ -78,6 +78,8 @@ const int BundleTag = 9;  // Predefined tag
 
 static vector<MilanLongInt> DEFAULT_VECTOR;
 
+#if !defined(SERIAL_MPI)
+
 // MPI type map
 template <typename T>
 MPI_Datatype TypeMap();
@@ -89,6 +91,7 @@ template <>
 inline MPI_Datatype TypeMap<double>() { return MPI_DOUBLE; }
 template <>
 inline MPI_Datatype TypeMap<float>() { return MPI_FLOAT; }
+#endif
 
 #ifdef __cplusplus
 extern "C"
diff --git a/amgprec/impl/aggregator/clean.cpp b/amgprec/impl/aggregator/clean.cpp
index f316aee7..87bb699a 100644
--- a/amgprec/impl/aggregator/clean.cpp
+++ b/amgprec/impl/aggregator/clean.cpp
@@ -1,6 +1,7 @@
 #include "MatchBoxPC.h"
 
 // TODO comment
+#if !defined(SERIAL_MPI)
 
 void clean(MilanLongInt NLVer,
            MilanInt myRank,
@@ -89,3 +90,4 @@ void clean(MilanLongInt NLVer,
         }
     }
 }
+#endif
diff --git a/amgprec/impl/aggregator/computeCandidateMate.cpp b/amgprec/impl/aggregator/computeCandidateMate.cpp
index 7d4e7ce8..a21db656 100644
--- a/amgprec/impl/aggregator/computeCandidateMate.cpp
+++ b/amgprec/impl/aggregator/computeCandidateMate.cpp
@@ -9,6 +9,8 @@
  * @param edgeLocWeight
  * @return
  */
+#if !defined(SERIAL_MPI)
+
 MilanLongInt firstComputeCandidateMate(MilanLongInt adj1,
                                        MilanLongInt adj2,
                                        MilanLongInt *verLocInd,
@@ -71,3 +73,4 @@ MilanLongInt computeCandidateMate(MilanLongInt adj1,
     
     return w;
 }
+#endif
diff --git a/amgprec/impl/aggregator/parallelComputeCandidateMateB.cpp b/amgprec/impl/aggregator/parallelComputeCandidateMateB.cpp
index ffb8d2a3..cf340da2 100644
--- a/amgprec/impl/aggregator/parallelComputeCandidateMateB.cpp
+++ b/amgprec/impl/aggregator/parallelComputeCandidateMateB.cpp
@@ -1,4 +1,5 @@
 #include "MatchBoxPC.h"
+#if !defined(SERIAL_MPI)
 
 void PARALLEL_COMPUTE_CANDIDATE_MATE_B(MilanLongInt NLVer,
                                               MilanLongInt *verLocPtr,
@@ -25,3 +26,4 @@ void PARALLEL_COMPUTE_CANDIDATE_MATE_B(MilanLongInt NLVer,
         }
     }
 }
+#endif
diff --git a/amgprec/impl/aggregator/processExposedVertex.cpp b/amgprec/impl/aggregator/processExposedVertex.cpp
index 2b38ec7a..0336bed5 100644
--- a/amgprec/impl/aggregator/processExposedVertex.cpp
+++ b/amgprec/impl/aggregator/processExposedVertex.cpp
@@ -1,4 +1,5 @@
 #include "MatchBoxPC.h"
+#if !defined(SERIAL_MPI)
 
 void PARALLEL_PROCESS_EXPOSED_VERTEX_B(MilanLongInt NLVer,
                                        MilanLongInt *candidateMate,
@@ -193,3 +194,4 @@ void PARALLEL_PROCESS_EXPOSED_VERTEX_B(MilanLongInt NLVer,
 
     } // End of parallel region
 }
+#endif
diff --git a/amgprec/impl/aggregator/processMatchedVertices.cpp b/amgprec/impl/aggregator/processMatchedVertices.cpp
index d9363c39..eadc0531 100644
--- a/amgprec/impl/aggregator/processMatchedVertices.cpp
+++ b/amgprec/impl/aggregator/processMatchedVertices.cpp
@@ -1,5 +1,6 @@
 #include "MatchBoxPC.h"
 
+#if !defined(SERIAL_MPI)
 void processMatchedVertices(
     MilanLongInt NLVer,
     vector<MilanLongInt> &UChunkBeingProcessed,
@@ -292,3 +293,4 @@ void processMatchedVertices(
 #endif
     } // End of parallel region
 }
+#endif
diff --git a/amgprec/impl/aggregator/processMatchedVerticesAndSendMessages.cpp b/amgprec/impl/aggregator/processMatchedVerticesAndSendMessages.cpp
index 469d7a16..922b5860 100644
--- a/amgprec/impl/aggregator/processMatchedVerticesAndSendMessages.cpp
+++ b/amgprec/impl/aggregator/processMatchedVerticesAndSendMessages.cpp
@@ -1,5 +1,6 @@
 #include "MatchBoxPC.h"
 //#define DEBUG_HANG_
+#if !defined(SERIAL_MPI)
 void processMatchedVerticesAndSendMessages(
 					   MilanLongInt NLVer,
 					   vector<MilanLongInt> &UChunkBeingProcessed,
@@ -306,3 +307,4 @@ void processMatchedVerticesAndSendMessages(
     cout << myRank<<" Done sending messages"<<endl;
 #endif
 }
+#endif
diff --git a/amgprec/impl/aggregator/processMessages.cpp b/amgprec/impl/aggregator/processMessages.cpp
index d2fccc94..2e3af9db 100644
--- a/amgprec/impl/aggregator/processMessages.cpp
+++ b/amgprec/impl/aggregator/processMessages.cpp
@@ -1,5 +1,6 @@
 #include "MatchBoxPC.h"
 //#define DEBUG_HANG_
+#if !defined(SERIAL_MPI)
 
 void processMessages(
     MilanLongInt NLVer,
@@ -313,3 +314,4 @@ void processMessages(
     
     return;
 }
+#endif
diff --git a/amgprec/impl/aggregator/sendBundledMessages.cpp b/amgprec/impl/aggregator/sendBundledMessages.cpp
index 80a88b94..07ea5834 100644
--- a/amgprec/impl/aggregator/sendBundledMessages.cpp
+++ b/amgprec/impl/aggregator/sendBundledMessages.cpp
@@ -1,5 +1,5 @@
 #include "MatchBoxPC.h"
-
+#if !defined(SERIAL_MPI)
 void sendBundledMessages(MilanLongInt *numGhostEdges,
                                 MilanInt *BufferSize,
                                 MilanLongInt *Buffer,
@@ -207,3 +207,4 @@ void sendBundledMessages(MilanLongInt *numGhostEdges,
 }
 }
 }
+#endif
diff --git a/amgprec/impl/level/amg_c_base_onelev_csetc.F90 b/amgprec/impl/level/amg_c_base_onelev_csetc.F90
index a372d972..99187cdf 100644
--- a/amgprec/impl/level/amg_c_base_onelev_csetc.F90
+++ b/amgprec/impl/level/amg_c_base_onelev_csetc.F90
@@ -42,6 +42,8 @@ subroutine amg_c_base_onelev_csetc(lv,what,val,info,pos,idx)
   use amg_c_base_aggregator_mod
   use amg_c_dec_aggregator_mod
   use amg_c_symdec_aggregator_mod
+#if !defined(SERIAL_MPI)
+#endif
   use amg_c_jac_smoother
   use amg_c_as_smoother
   use amg_c_diag_solver
@@ -246,6 +248,8 @@ subroutine amg_c_base_onelev_csetc(lv,what,val,info,pos,idx)
       if (info == 0) deallocate(lv%aggr,stat=info)
       if (info /= 0) then
         info = psb_err_internal_error_
+        call psb_errpush(info,name,a_err='aggregator deallocation?')
+        goto 9999
         return
       end if
     end if
@@ -255,8 +259,16 @@ subroutine amg_c_base_onelev_csetc(lv,what,val,info,pos,idx)
       allocate(amg_c_dec_aggregator_type :: lv%aggr, stat=info)
     case('SYMDEC')
       allocate(amg_c_symdec_aggregator_type :: lv%aggr, stat=info)
-    case default
+#if !defined(SERIAL_MPI)
+#endif
+  case default
       info =  psb_err_internal_error_
+#if !defined(SERIAL_MPI)
+      call psb_errpush(info,name,a_err='Unsupported PAR_AGGR_ALG')
+#else
+      call psb_errpush(info,name,a_err='PAR_AGGR_ALG unsupported (SERIAL_MPI on)')
+#endif
+      goto 9999
     end select
     if (info == psb_success_) call lv%aggr%default()
 
diff --git a/amgprec/impl/level/amg_d_base_onelev_csetc.F90 b/amgprec/impl/level/amg_d_base_onelev_csetc.F90
index 94f45276..e3e9b31c 100644
--- a/amgprec/impl/level/amg_d_base_onelev_csetc.F90
+++ b/amgprec/impl/level/amg_d_base_onelev_csetc.F90
@@ -42,7 +42,9 @@ subroutine amg_d_base_onelev_csetc(lv,what,val,info,pos,idx)
   use amg_d_base_aggregator_mod
   use amg_d_dec_aggregator_mod
   use amg_d_symdec_aggregator_mod
+#if !defined(SERIAL_MPI)
   use amg_d_parmatch_aggregator_mod
+#endif
   use amg_d_jac_smoother
   use amg_d_as_smoother
   use amg_d_diag_solver
@@ -267,6 +269,8 @@ subroutine amg_d_base_onelev_csetc(lv,what,val,info,pos,idx)
       if (info == 0) deallocate(lv%aggr,stat=info)
       if (info /= 0) then
         info = psb_err_internal_error_
+        call psb_errpush(info,name,a_err='aggregator deallocation?')
+        goto 9999
         return
       end if
     end if
@@ -276,10 +280,18 @@ subroutine amg_d_base_onelev_csetc(lv,what,val,info,pos,idx)
       allocate(amg_d_dec_aggregator_type :: lv%aggr, stat=info)
     case('SYMDEC')
       allocate(amg_d_symdec_aggregator_type :: lv%aggr, stat=info)
+#if !defined(SERIAL_MPI)
     case('COUP','COUPLED')
       allocate(amg_d_parmatch_aggregator_type :: lv%aggr, stat=info)
-    case default
+#endif
+  case default
       info =  psb_err_internal_error_
+#if !defined(SERIAL_MPI)
+      call psb_errpush(info,name,a_err='Unsupported PAR_AGGR_ALG')
+#else
+      call psb_errpush(info,name,a_err='PAR_AGGR_ALG unsupported (SERIAL_MPI on)')
+#endif
+      goto 9999
     end select
     if (info == psb_success_) call lv%aggr%default()
 
diff --git a/amgprec/impl/level/amg_s_base_onelev_csetc.F90 b/amgprec/impl/level/amg_s_base_onelev_csetc.F90
index 60329291..5f3852bc 100644
--- a/amgprec/impl/level/amg_s_base_onelev_csetc.F90
+++ b/amgprec/impl/level/amg_s_base_onelev_csetc.F90
@@ -42,7 +42,9 @@ subroutine amg_s_base_onelev_csetc(lv,what,val,info,pos,idx)
   use amg_s_base_aggregator_mod
   use amg_s_dec_aggregator_mod
   use amg_s_symdec_aggregator_mod
+#if !defined(SERIAL_MPI)
   use amg_s_parmatch_aggregator_mod
+#endif
   use amg_s_jac_smoother
   use amg_s_as_smoother
   use amg_s_diag_solver
@@ -247,6 +249,8 @@ subroutine amg_s_base_onelev_csetc(lv,what,val,info,pos,idx)
       if (info == 0) deallocate(lv%aggr,stat=info)
       if (info /= 0) then
         info = psb_err_internal_error_
+        call psb_errpush(info,name,a_err='aggregator deallocation?')
+        goto 9999
         return
       end if
     end if
@@ -256,10 +260,18 @@ subroutine amg_s_base_onelev_csetc(lv,what,val,info,pos,idx)
       allocate(amg_s_dec_aggregator_type :: lv%aggr, stat=info)
     case('SYMDEC')
       allocate(amg_s_symdec_aggregator_type :: lv%aggr, stat=info)
+#if !defined(SERIAL_MPI)
     case('COUP','COUPLED')
       allocate(amg_s_parmatch_aggregator_type :: lv%aggr, stat=info)
-    case default
+#endif
+  case default
       info =  psb_err_internal_error_
+#if !defined(SERIAL_MPI)
+      call psb_errpush(info,name,a_err='Unsupported PAR_AGGR_ALG')
+#else
+      call psb_errpush(info,name,a_err='PAR_AGGR_ALG unsupported (SERIAL_MPI on)')
+#endif
+      goto 9999
     end select
     if (info == psb_success_) call lv%aggr%default()
 
diff --git a/amgprec/impl/level/amg_z_base_onelev_csetc.F90 b/amgprec/impl/level/amg_z_base_onelev_csetc.F90
index 5ca4233c..f2a54a8c 100644
--- a/amgprec/impl/level/amg_z_base_onelev_csetc.F90
+++ b/amgprec/impl/level/amg_z_base_onelev_csetc.F90
@@ -42,6 +42,8 @@ subroutine amg_z_base_onelev_csetc(lv,what,val,info,pos,idx)
   use amg_z_base_aggregator_mod
   use amg_z_dec_aggregator_mod
   use amg_z_symdec_aggregator_mod
+#if !defined(SERIAL_MPI)
+#endif
   use amg_z_jac_smoother
   use amg_z_as_smoother
   use amg_z_diag_solver
@@ -266,6 +268,8 @@ subroutine amg_z_base_onelev_csetc(lv,what,val,info,pos,idx)
       if (info == 0) deallocate(lv%aggr,stat=info)
       if (info /= 0) then
         info = psb_err_internal_error_
+        call psb_errpush(info,name,a_err='aggregator deallocation?')
+        goto 9999
         return
       end if
     end if
@@ -275,8 +279,16 @@ subroutine amg_z_base_onelev_csetc(lv,what,val,info,pos,idx)
       allocate(amg_z_dec_aggregator_type :: lv%aggr, stat=info)
     case('SYMDEC')
       allocate(amg_z_symdec_aggregator_type :: lv%aggr, stat=info)
-    case default
+#if !defined(SERIAL_MPI)
+#endif
+  case default
       info =  psb_err_internal_error_
+#if !defined(SERIAL_MPI)
+      call psb_errpush(info,name,a_err='Unsupported PAR_AGGR_ALG')
+#else
+      call psb_errpush(info,name,a_err='PAR_AGGR_ALG unsupported (SERIAL_MPI on)')
+#endif
+      goto 9999
     end select
     if (info == psb_success_) call lv%aggr%default()