diff --git a/BaseLib/CPUTime.h b/BaseLib/CPUTime.h
index fc72f563a2ec2ee4c869172250723f2dd3fc8b80..ba9a5b3b5ec50cf2686c3d937c2d5eaacca38dc1 100644
--- a/BaseLib/CPUTime.h
+++ b/BaseLib/CPUTime.h
@@ -32,7 +32,7 @@ class CPUTime
         }
 
         /// Get the elapsed time after started.
-        const double elapsed()
+        double elapsed() const
         {
             return (clock() - _start_time)/static_cast<double>(CLOCKS_PER_SEC);
         }
diff --git a/BaseLib/RunTime.h b/BaseLib/RunTime.h
index cb67269a0b4269a21113accc197b44c72497bbac..4a3a647673023035fecee1ce11fb1096d0cb6cc9 100644
--- a/BaseLib/RunTime.h
+++ b/BaseLib/RunTime.h
@@ -50,7 +50,7 @@ class RunTime
         }
 
         /// Get the elapsed time after started.
-        const double elapsed()
+        double elapsed() const
         {
 #if defined(USE_MPI)
             return MPI_Wtime() - _start_time;
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4f63552715b3cba73a7184d3064b7082118ecac5..3ded1f940c79af67e6155d710bce4f380ab7228e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -117,15 +117,6 @@ INCLUDE_DIRECTORIES( SYSTEM ${CMAKE_CURRENT_SOURCE_DIR}/ThirdParty/gtest/include
 INCLUDE_DIRECTORIES( SYSTEM ${CMAKE_CURRENT_SOURCE_DIR}/ThirdParty/quickcheck )
 INCLUDE_DIRECTORIES( SYSTEM ${CMAKE_CURRENT_BINARY_DIR}/ThirdParty/zlib )
 
-# Use MPI
-IF(OGS_USE_MPI)
-	IF(WIN32)
-		ADD_DEFINITIONS(/DUSE_MPI)
-	ELSE()  
-		ADD_DEFINITIONS(-DUSE_MPI)
-	ENDIF()
-ENDIF()
-
 IF(OGS_USE_LIS)
     ADD_DEFINITIONS(-DUSE_LIS)
     INCLUDE_DIRECTORIES(SYSTEM ${LIS_INCLUDE_DIR})
@@ -137,6 +128,15 @@ IF(OGS_USE_PETSC)
     SET(OGS_USE_MPI ON)
 ENDIF()
 
+# Use MPI
+IF(OGS_USE_MPI)
+	IF(WIN32)
+		ADD_DEFINITIONS(/DUSE_MPI)
+	ELSE()  
+		ADD_DEFINITIONS(-DUSE_MPI)
+	ENDIF()
+ENDIF()
+
 IF(OGS_USE_EIGEN)
 #	ADD_DEFINITIONS(-DEIGEN_DEFAULT_DENSE_INDEX_TYPE=std::size_t)
 	ADD_DEFINITIONS(-DEIGEN_INITIALIZE_MATRICES_BY_ZERO)
diff --git a/scripts/cmake/Find.cmake b/scripts/cmake/Find.cmake
index b6cd99a30eba5f27b5b27da552dc5bd8b63dde6c..42b02d5ee4080c0af4c32ac171edbe1aff11e4c7 100644
--- a/scripts/cmake/Find.cmake
+++ b/scripts/cmake/Find.cmake
@@ -116,11 +116,6 @@ IF(OGS_USE_LIS)
 	FIND_PACKAGE( LIS REQUIRED )
 ENDIF()
 
-## Check MPI package
-IF(OGS_USE_MPI)
-	FIND_PACKAGE(MPI REQUIRED)
-ENDIF()
-
 IF(OGS_USE_PETSC)
     MESSAGE (STATUS  "Configuring for PETSc" )
 
@@ -147,6 +142,9 @@ IF(OGS_USE_PETSC)
     
 ENDIF()
 
+## Check MPI package
 IF(OGS_USE_MPI)
+	FIND_PACKAGE(MPI REQUIRED)
 	INCLUDE_DIRECTORIES(SYSTEM ${MPI_CXX_INCLUDE_PATH})
 ENDIF()
+