diff --git a/etc/settings.csh b/etc/settings.csh
index 7ebab4e73d..5670e449a6 100644
--- a/etc/settings.csh
+++ b/etc/settings.csh
@@ -134,7 +134,7 @@ switch ("$WM_MPLIB")
 case OPENMPI:
     set mpi_version=openmpi-1.4.1
     setenv MPI_HOME $WM_THIRD_PARTY_DIR/$mpi_version
-    setenv MPI_ARCH_PATH $WM_THIRD_PARTY_DIR/platforms/$WM_OPTIONS/$mpi_version
+    setenv MPI_ARCH_PATH $WM_THIRD_PARTY_DIR/platforms/$WM_ARCH$WM_COMPILER/$mpi_version
 
     # Tell OpenMPI where to find its install directory
     setenv OPAL_PREFIX $MPI_ARCH_PATH
@@ -148,9 +148,7 @@ case OPENMPI:
     breaksw
 
 case SYSTEMOPENMPI:
-
     # This uses the installed openmpi. It needs mpicc installed!
-
     set mpi_version=openmpi-system
 
     # Set compilation flags here instead of in wmake/rules/../mplibSYSTEMOPENMPI
@@ -174,7 +172,7 @@ case SYSTEMOPENMPI:
 case MPICH:
     set mpi_version=mpich2-1.1.1p1
     setenv MPI_HOME $WM_THIRD_PARTY_DIR/$mpi_version
-    setenv MPI_ARCH_PATH $WM_THIRD_PARTY_DIR/platforms/$WM_OPTIONS/$mpi_version
+    setenv MPI_ARCH_PATH $WM_THIRD_PARTY_DIR/platforms/$WM_ARCH$WM_COMPILER/$mpi_version
 
     _foamAddPath    $MPI_ARCH_PATH/bin
     _foamAddLib     $MPI_ARCH_PATH/lib
diff --git a/etc/settings.sh b/etc/settings.sh
index 208dfa2a0e..6c787386d1 100644
--- a/etc/settings.sh
+++ b/etc/settings.sh
@@ -170,7 +170,7 @@ case "$WM_MPLIB" in
 OPENMPI)
     mpi_version=openmpi-1.4.1
     export MPI_HOME=$WM_THIRD_PARTY_DIR/$mpi_version
-    export MPI_ARCH_PATH=$WM_THIRD_PARTY_DIR/platforms/$WM_OPTIONS/$mpi_version
+    export MPI_ARCH_PATH=$WM_THIRD_PARTY_DIR/platforms/$WM_ARCH$WM_COMPILER/$mpi_version
 
     # Tell OpenMPI where to find its install directory
     export OPAL_PREFIX=$MPI_ARCH_PATH
@@ -184,6 +184,7 @@ OPENMPI)
     ;;
 
 SYSTEMOPENMPI)
+    # This uses the installed openmpi. It needs mpicc installed!
     mpi_version=openmpi-system
 
     # Set compilation flags here instead of in wmake/rules/../mplibSYSTEMOPENMPI
@@ -208,7 +209,7 @@ SYSTEMOPENMPI)
 MPICH)
     mpi_version=mpich2-1.1.1p1
     export MPI_HOME=$WM_THIRD_PARTY_DIR/$mpi_version
-    export MPI_ARCH_PATH=$WM_THIRD_PARTY_DIR/platforms/$WM_OPTIONS/$mpi_version
+    export MPI_ARCH_PATH=$WM_THIRD_PARTY_DIR/platforms/$WM_ARCH$WM_COMPILER/$mpi_version
 
     _foamAddPath    $MPI_ARCH_PATH/bin
     _foamAddLib     $MPI_ARCH_PATH/lib
diff --git a/src/Pstream/Allwmake b/src/Pstream/Allwmake
index a01538cc38..cc3329e384 100755
--- a/src/Pstream/Allwmake
+++ b/src/Pstream/Allwmake
@@ -10,7 +10,8 @@ case "$WM_MPLIB" in
     echo
     echo "Note: ignore spurious warnings about missing mpicxx.h headers"
     set -x
-    (WM_OPTIONS=${WM_OPTIONS}$WM_MPLIB; wmake libso mpi)
+    # force compilation into qualified directory
+    WM_OPTIONS=${WM_OPTIONS}$WM_MPLIB  wmake libso mpi
     ;;
 
 #GAMMA)