diff --git a/reco/KF/KF.cmake b/reco/KF/KF.cmake
index a9c0b7e63a6bdca4d21fc95e69e128c578181791..53477deb37f0a6c28dd744143e52a9b9897fa3d2 100644
--- a/reco/KF/KF.cmake
+++ b/reco/KF/KF.cmake
@@ -122,22 +122,22 @@ Interface/CbmGlobalTrackFitterKF.h
 #CbmKFParticleInterface.h
 )
 
-If (APPLE)
+If(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
   ADD_DEFINITIONS(-Wall -Wsign-promo -Wctor-dtor-privacy -Wreorder -Wno-deprecated -Wno-parentheses -DDO_TPCCATRACKER_EFF_PERFORMANCE -DNonhomogeneousField -DCBM -DUSE_TIMERS) # -Weffc++ -Wnon-virtual-dtor -Woverloaded-virtual -Wold-style-cast   : wait for other parts of cbmroot\root.
   #---Check for compiler flags
-  CHECK_CXX_COMPILER_FLAG("-Wno-pmf-conversions" HAS_PMF)
+  CHECK_CXX_COMPILER_FLAG("-Werror -Wno-pmf-conversions" HAS_PMF)
   If(HAS_PMF)
     ADD_DEFINITIONS(-Wno-pmf-conversions)
   EndIf()
-  CHECK_CXX_COMPILER_FLAG("-Wstrict-null-sentinel" HAS_SENTINEL)
+  CHECK_CXX_COMPILER_FLAG("-Werror -Wstrict-null-sentinel" HAS_SENTINEL)
   If(HAS_SENTINEL)
     ADD_DEFINITIONS(-Wstrict-null-sentinel)
   EndIf()
-  CHECK_CXX_COMPILER_FLAG("-Wno-non-template-friend" HAS_TEMPLATE_FRIEND)
+  CHECK_CXX_COMPILER_FLAG("-Werror -Wno-non-template-friend" HAS_TEMPLATE_FRIEND)
   If(HAS_TEMPLATE_FRIEND)
     ADD_DEFINITIONS(-Wno-non-template-friend)
   EndIf()
-  CHECK_CXX_COMPILER_FLAG("-Wno-pragmas" HAS_PRAGMA)
+  CHECK_CXX_COMPILER_FLAG("-Werror -Wno-pragmas" HAS_PRAGMA)
   If(HAS_PRAGMA)
     ADD_DEFINITIONS(-Wno-pragmas)
   EndIf()
diff --git a/reco/KF/KFParticleInterface.cmake b/reco/KF/KFParticleInterface.cmake
index a8efb568521b87b12fbbcfb1e75f31a418c51bb9..7fb7e1d11a6678e0ddf3c5601e04491964442ea6 100644
--- a/reco/KF/KFParticleInterface.cmake
+++ b/reco/KF/KFParticleInterface.cmake
@@ -65,22 +65,22 @@ CbmKFParticleFinderQa.h
 CbmKFParticleInterface.h
 )
 
-If (APPLE)
+If(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
   ADD_DEFINITIONS(-Wall -Wsign-promo -Wctor-dtor-privacy -Wreorder -Wno-deprecated -Wno-parentheses -DDO_TPCCATRACKER_EFF_PERFORMANCE -DNonhomogeneousField -DCBM -DUSE_TIMERS) # -Weffc++ -Wnon-virtual-dtor -Woverloaded-virtual -Wold-style-cast   : wait for other parts of cbmroot\root.
   #---Check for compiler flags
-  CHECK_CXX_COMPILER_FLAG("-Wno-pmf-conversions" HAS_PMF)
+  CHECK_CXX_COMPILER_FLAG("-Werror -Wno-pmf-conversions" HAS_PMF)
   If(HAS_PMF)
     ADD_DEFINITIONS(-Wno-pmf-conversions)
   EndIf()
-  CHECK_CXX_COMPILER_FLAG("-Wstrict-null-sentinel" HAS_SENTINEL)
+  CHECK_CXX_COMPILER_FLAG("-Werror -Wstrict-null-sentinel" HAS_SENTINEL)
   If(HAS_SENTINEL)
     ADD_DEFINITIONS(-Wstrict-null-sentinel)
   EndIf()
-  CHECK_CXX_COMPILER_FLAG("-Wno-non-template-friend" HAS_TEMPLATE_FRIEND)
+  CHECK_CXX_COMPILER_FLAG("-Werror -Wno-non-template-friend" HAS_TEMPLATE_FRIEND)
   If(HAS_TEMPLATE_FRIEND)
     ADD_DEFINITIONS(-Wno-non-template-friend)
   EndIf()
-  CHECK_CXX_COMPILER_FLAG("-Wno-pragmas" HAS_PRAGMA)
+  CHECK_CXX_COMPILER_FLAG("-Werror -Wno-pragmas" HAS_PRAGMA)
   If(HAS_PRAGMA)
     ADD_DEFINITIONS(-Wno-pragmas)
   EndIf()
@@ -89,12 +89,12 @@ Else()
 EndIf()
 
 IF (SSE_FOUND)
-  Message(STATUS "KF will be compiled with SSE support")
+  Message(STATUS "KFParticleInterface will be compiled with SSE support")
   ADD_DEFINITIONS(-DHAVE_SSE)
   SET_SOURCE_FILES_PROPERTIES(${SRCS} PROPERTIES COMPILE_FLAGS 
   "-msse -O3")
 ELSE (SSE_FOUND)
-  MESSAGE(STATUS "KF will be compiled without SSE support")
+  MESSAGE(STATUS "KFParticleInterface will be compiled without SSE support")
   SET_SOURCE_FILES_PROPERTIES(${SRCS} PROPERTIES COMPILE_FLAGS 
   "-O3")
 ENDIF (SSE_FOUND)
diff --git a/reco/KF/KFQA.cmake b/reco/KF/KFQA.cmake
index f94bbe426fbdc7d8ad90c88eb1cf1cff5cd64641..339202e24feaa760a9575894fef61c0cfb17d1de 100644
--- a/reco/KF/KFQA.cmake
+++ b/reco/KF/KFQA.cmake
@@ -66,22 +66,22 @@ KFQA/CbmKFPartEfficiencies.h
 KFQA/KFParticleMatch.h
 )
 
-If (APPLE)
+If(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
   ADD_DEFINITIONS(-Wall -Wsign-promo -Wctor-dtor-privacy -Wreorder -Wno-deprecated -Wno-parentheses -DDO_TPCCATRACKER_EFF_PERFORMANCE -DNonhomogeneousField -DCBM -DUSE_TIMERS) # -Weffc++ -Wnon-virtual-dtor -Woverloaded-virtual -Wold-style-cast   : wait for other parts of cbmroot\root.
   #---Check for compiler flags
-  CHECK_CXX_COMPILER_FLAG("-Wno-pmf-conversions" HAS_PMF)
+  CHECK_CXX_COMPILER_FLAG("-Werror -Wno-pmf-conversions" HAS_PMF)
   If(HAS_PMF)
     ADD_DEFINITIONS(-Wno-pmf-conversions)
   EndIf()
-  CHECK_CXX_COMPILER_FLAG("-Wstrict-null-sentinel" HAS_SENTINEL)
+  CHECK_CXX_COMPILER_FLAG("-Werror -Wstrict-null-sentinel" HAS_SENTINEL)
   If(HAS_SENTINEL)
     ADD_DEFINITIONS(-Wstrict-null-sentinel)
   EndIf()
-  CHECK_CXX_COMPILER_FLAG("-Wno-non-template-friend" HAS_TEMPLATE_FRIEND)
+  CHECK_CXX_COMPILER_FLAG("-Werror -Wno-non-template-friend" HAS_TEMPLATE_FRIEND)
   If(HAS_TEMPLATE_FRIEND)
     ADD_DEFINITIONS(-Wno-non-template-friend)
   EndIf()
-  CHECK_CXX_COMPILER_FLAG("-Wno-pragmas" HAS_PRAGMA)
+  CHECK_CXX_COMPILER_FLAG("-Werror -Wno-pragmas" HAS_PRAGMA)
   If(HAS_PRAGMA)
     ADD_DEFINITIONS(-Wno-pragmas)
   EndIf()
@@ -90,12 +90,12 @@ Else()
 EndIf()
 
 IF (SSE_FOUND)
-  Message(STATUS "KF will be compiled with SSE support")
+  Message(STATUS "KFQA will be compiled with SSE support")
   ADD_DEFINITIONS(-DHAVE_SSE)
   SET_SOURCE_FILES_PROPERTIES(${SRCS} PROPERTIES COMPILE_FLAGS 
   "-msse -O3")
 ELSE (SSE_FOUND)
-  MESSAGE(STATUS "KF will be compiled without SSE support")
+  MESSAGE(STATUS "KFQA will be compiled without SSE support")
   SET_SOURCE_FILES_PROPERTIES(${SRCS} PROPERTIES COMPILE_FLAGS 
   "-O3")
 ENDIF (SSE_FOUND)
diff --git a/reco/L1/CMakeLists.txt b/reco/L1/CMakeLists.txt
index 291f5f7ce25de9b670b0f92d00b207220f78f4d3..e3d4cc9299dc3d392338d2b425e0ac23591b3d69 100644
--- a/reco/L1/CMakeLists.txt
+++ b/reco/L1/CMakeLists.txt
@@ -190,27 +190,23 @@ qa/CbmTrackerInputQaTrd.h
 
 
 
-If(APPLE)
+If(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
   ADD_DEFINITIONS(-Wall -Wsign-promo -Wctor-dtor-privacy -Wreorder -Wno-deprecated -Wno-parentheses) #   -Weffc++ -Wnon-virtual-dtor -Woverloaded-virtual -Wold-style-cast : wait for other parts of cbmroot\root.
 #-- - Check for compiler flags
-  CHECK_CXX_COMPILER_FLAG("-Wno-pmf-conversions" HAS_PMF)
+  CHECK_CXX_COMPILER_FLAG("-Werror -Wno-pmf-conversions" HAS_PMF)
   If(HAS_PMF)
     ADD_DEFINITIONS(-Wno-pmf-conversions)
   EndIf()
-  CHECK_CXX_COMPILER_FLAG("-Wstrict-null-sentinel" HAS_SENTINEL)
+  CHECK_CXX_COMPILER_FLAG("-Werror -Wstrict-null-sentinel" HAS_SENTINEL)
   If(HAS_SENTINEL)
     ADD_DEFINITIONS(-Wstrict-null-sentinel)
   EndIf()
-  CHECK_CXX_COMPILER_FLAG("-Wno-non-template-friend" HAS_TEMPLATE_FRIEND)
+  CHECK_CXX_COMPILER_FLAG("-Werror -Wno-non-template-friend" HAS_TEMPLATE_FRIEND)
   If(HAS_TEMPLATE_FRIEND)
     ADD_DEFINITIONS(-Wno-non-template-friend)
   EndIf()
-
-
 Else()
-  
   ADD_DEFINITIONS(-Wall -Wsign-promo  -Wno-pmf-conversions -Wctor-dtor-privacy -Wreorder -Wno-deprecated -Wstrict-null-sentinel -Wno-non-template-friend -Wno-parentheses) #   -Weffc++ -Wnon-virtual-dtor -Woverloaded-virtual -Wold-style-cast : wait for other parts of cbmroot\root. 
-
 EndIf()
 
 
diff --git a/reco/eventbuilder/CMakeLists.txt b/reco/eventbuilder/CMakeLists.txt
index 1008551332c6b6ea9fb269713b9f1998d8735126..9c19042b0d7f23b71c05d022a321ac7872dcc786 100644
--- a/reco/eventbuilder/CMakeLists.txt
+++ b/reco/eventbuilder/CMakeLists.txt
@@ -79,9 +79,9 @@ IF (SSE_FOUND)
   ADD_DEFINITIONS(-DHAVE_SSE)
   SET_SOURCE_FILES_PROPERTIES(${SRCS} PROPERTIES COMPILE_FLAGS 
   "-msse -O3")
-  Message(STATUS "L1 will be compiled with SSE support")
+  Message(STATUS "eventbuilder will be compiled with SSE support")
 ELSE (SSE_FOUND)
-  Message(STATUS "L1 will be compiled without SSE support")
+  Message(STATUS "eventbuilder will be compiled without SSE support")
   SET_SOURCE_FILES_PROPERTIES(${SRCS} PROPERTIES COMPILE_FLAGS 
   "-O3")
 ENDIF (SSE_FOUND)