diff --git a/src/external/BMWtools/CMakeLists.txt b/src/external/BMWtools/CMakeLists.txt
index c7b49e80c..a8e9b9cbc 100644
--- a/src/external/BMWtools/CMakeLists.txt
+++ b/src/external/BMWtools/CMakeLists.txt
@@ -45,9 +45,6 @@ target_include_directories(
     $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
 )
 
-#--- add compile options for optimization -------------------------------------
-target_compile_options(BMWtools PUBLIC -O3)
-
 #--- add library dependencies -------------------------------------------------
 target_link_libraries(BMWtools ${ROOT_LIBRARIES} cuba)
 
diff --git a/src/external/MagProximity/CMakeLists.txt b/src/external/MagProximity/CMakeLists.txt
index 817ab8e2e..acac4032b 100644
--- a/src/external/MagProximity/CMakeLists.txt
+++ b/src/external/MagProximity/CMakeLists.txt
@@ -51,9 +51,6 @@ set_target_properties(PMagProximityFitter
     VERSION ${P_MAG_PROXIMITY_FITTER_VERSION}
 )
 
-#--- add compile options for optimization -------------------------------------
-target_compile_options(PMagProximityFitter PUBLIC -O3)
-
 #--- add library dependencies -------------------------------------------------
 target_link_libraries(PMagProximityFitter ${FFTW3_LIBRARY} ${ROOT_LIBRARIES} PUserFcnBase)
 
diff --git a/src/external/MuSR_software/Class_MuSR_PSI/CMakeLists.txt b/src/external/MuSR_software/Class_MuSR_PSI/CMakeLists.txt
index 288d30e69..6822f6000 100644
--- a/src/external/MuSR_software/Class_MuSR_PSI/CMakeLists.txt
+++ b/src/external/MuSR_software/Class_MuSR_PSI/CMakeLists.txt
@@ -27,9 +27,6 @@ set_target_properties(Class_MuSR_PSI
     VERSION ${PSIBIN_VERSION}
 )
 
-#--- add compile options for optimization -------------------------------------
-target_compile_options(Class_MuSR_PSI PUBLIC -O3)
-
 #--- install Class_MuSR_PSI solib ---------------------------------------------
 install(TARGETS Class_MuSR_PSI DESTINATION lib)
 
diff --git a/src/external/MusrRoot/CMakeLists.txt b/src/external/MusrRoot/CMakeLists.txt
index 220770ad0..dfe255b56 100644
--- a/src/external/MusrRoot/CMakeLists.txt
+++ b/src/external/MusrRoot/CMakeLists.txt
@@ -31,9 +31,6 @@ target_include_directories(
   TMusrRunHeader BEFORE PRIVATE $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
 )
 
-#--- add compile options for optimization -------------------------------------
-target_compile_options(TMusrRunHeader PUBLIC -O3)
-
 #--- add library dependencies -------------------------------------------------
 target_link_libraries(TMusrRunHeader ${ROOT_LIBRARIES})
 
diff --git a/src/external/Nonlocal/CMakeLists.txt b/src/external/Nonlocal/CMakeLists.txt
index 0a8e02c66..694cdaabc 100644
--- a/src/external/Nonlocal/CMakeLists.txt
+++ b/src/external/Nonlocal/CMakeLists.txt
@@ -52,9 +52,6 @@ set_target_properties(PNL_PippardFitter
     VERSION ${PNL_PIPPARDFITTER_VERSION}
 )
 
-#--- add compile options for optimization -------------------------------------
-target_compile_options(PNL_PippardFitter PUBLIC -O3)
-
 #--- add library dependencies -------------------------------------------------
 target_link_libraries(PNL_PippardFitter ${FFTW3_LIBRARY} ${ROOT_LIBRARIES} PUserFcnBase)
 
diff --git a/src/external/TLemRunHeader/CMakeLists.txt b/src/external/TLemRunHeader/CMakeLists.txt
index 8e374480a..d3bfb4365 100644
--- a/src/external/TLemRunHeader/CMakeLists.txt
+++ b/src/external/TLemRunHeader/CMakeLists.txt
@@ -36,9 +36,6 @@ target_include_directories(
   TLemRunHeader BEFORE PRIVATE $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
 )
 
-#--- add compile options for optimization -------------------------------------
-target_compile_options(TLemRunHeader PUBLIC -O3)
-
 #--- add library dependencies -------------------------------------------------
 target_link_libraries(TLemRunHeader ${ROOT_LIBRARIES})
 
diff --git a/src/external/libBNMR/CMakeLists.txt b/src/external/libBNMR/CMakeLists.txt
index b2c5ff8c3..520ad368e 100644
--- a/src/external/libBNMR/CMakeLists.txt
+++ b/src/external/libBNMR/CMakeLists.txt
@@ -30,9 +30,6 @@ set_target_properties(BNMR
     VERSION "1.0.0"
 )
 
-#--- add compile options for optimization -------------------------------------
-target_compile_options(BNMR PUBLIC -O3)
-
 #--- add library dependencies -------------------------------------------------
 target_link_libraries(BNMR ${ROOT_LIBRARIES} PUserFcnBase)
 
diff --git a/src/external/libCalcMeanFieldsLEM/CMakeLists.txt b/src/external/libCalcMeanFieldsLEM/CMakeLists.txt
index 01e9c58f1..0916986b6 100644
--- a/src/external/libCalcMeanFieldsLEM/CMakeLists.txt
+++ b/src/external/libCalcMeanFieldsLEM/CMakeLists.txt
@@ -48,9 +48,6 @@ target_include_directories(
     $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
 )
 
-#--- add compile options for optimization -------------------------------------
-target_compile_options(CalcMeanFieldsLEM PUBLIC -O3)
-
 #--- add library dependencies -------------------------------------------------
 target_link_libraries(CalcMeanFieldsLEM 
   ${FFTW3_LIBRARY} ${ROOT_LIBRARIES} BMWtools FitPofB PUserFcnBase
diff --git a/src/external/libFitPofB/classes/CMakeLists.txt b/src/external/libFitPofB/classes/CMakeLists.txt
index e673f369e..547606677 100644
--- a/src/external/libFitPofB/classes/CMakeLists.txt
+++ b/src/external/libFitPofB/classes/CMakeLists.txt
@@ -79,9 +79,6 @@ target_include_directories(
     $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/../include>
 )
 
-#--- add compile options for optimization -------------------------------------
-target_compile_options(FitPofB PUBLIC -O3)
-
 #--- add library dependencies -------------------------------------------------
 target_link_libraries(FitPofB 
     ${FFTW3_LIBRARY} ${FFTW3F_LIBRARY} ${ROOT_LIBRARIES} 
diff --git a/src/external/libGapIntegrals/CMakeLists.txt b/src/external/libGapIntegrals/CMakeLists.txt
index 8935ab87c..63fb1b057 100644
--- a/src/external/libGapIntegrals/CMakeLists.txt
+++ b/src/external/libGapIntegrals/CMakeLists.txt
@@ -45,9 +45,6 @@ target_include_directories(
     $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
 )
 
-#--- add compile options for optimization -------------------------------------
-target_compile_options(GapIntegrals PUBLIC -O3)
-
 #--- add library dependencies -------------------------------------------------
 target_link_libraries(GapIntegrals 
   ${GSL_LIBRARIES} ${FFTW3F_LIBRARY} ${ROOT_LIBRARIES} 
diff --git a/src/external/libLFRelaxation/CMakeLists.txt b/src/external/libLFRelaxation/CMakeLists.txt
index 6c4d55048..af9274f3b 100644
--- a/src/external/libLFRelaxation/CMakeLists.txt
+++ b/src/external/libLFRelaxation/CMakeLists.txt
@@ -45,9 +45,6 @@ target_include_directories(
     $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
 )
 
-#--- add compile options for optimization -------------------------------------
-target_compile_options(LFRelaxation PUBLIC -O3)
-
 #--- add library dependencies -------------------------------------------------
 target_link_libraries(LFRelaxation ${GSL_LIBRARIES} ${FFTW3F_LIBRARY} 
    ${ROOT_LIBRARIES} PUserFcnBase cuba BMWtools
diff --git a/src/external/libPhotoMeissner/classes/CMakeLists.txt b/src/external/libPhotoMeissner/classes/CMakeLists.txt
index 8d226aebe..80d284a2d 100644
--- a/src/external/libPhotoMeissner/classes/CMakeLists.txt
+++ b/src/external/libPhotoMeissner/classes/CMakeLists.txt
@@ -49,9 +49,6 @@ target_include_directories(
     $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/../include>
 )
 
-#--- add compile options for optimization -------------------------------------
-target_compile_options(PPhotoMeissner PUBLIC -O3)
-
 #--- add library dependencies -------------------------------------------------
 target_link_libraries(PPhotoMeissner 
    ${FFTW3_LIBRARY} ${GSL_LIBRARY} ${ROOT_LIBRARIES} PUserFcnBase
diff --git a/src/external/libSpinValve/classes/CMakeLists.txt b/src/external/libSpinValve/classes/CMakeLists.txt
index 8f3ceaa3c..94711cd99 100644
--- a/src/external/libSpinValve/classes/CMakeLists.txt
+++ b/src/external/libSpinValve/classes/CMakeLists.txt
@@ -49,9 +49,6 @@ target_include_directories(
     $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/../include>
 )
 
-#--- add compile options for optimization -------------------------------------
-target_compile_options(PSpinValve PUBLIC -O3)
-
 #--- add library dependencies -------------------------------------------------
 target_link_libraries(PSpinValve ${FFTW3_LIBRARY} ${ROOT_LIBRARIES} PUserFcnBase)
 
diff --git a/src/external/libZFRelaxation/CMakeLists.txt b/src/external/libZFRelaxation/CMakeLists.txt
index 77a39917d..6c5fba1f0 100644
--- a/src/external/libZFRelaxation/CMakeLists.txt
+++ b/src/external/libZFRelaxation/CMakeLists.txt
@@ -45,9 +45,6 @@ target_include_directories(
     $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
 )
 
-#--- add compile options for optimization -------------------------------------
-target_compile_options(ZFRelaxation PUBLIC -O3)
-
 #--- add library dependencies -------------------------------------------------
 target_link_libraries(ZFRelaxation 
   ${FFTW3_LIBRARY} ${ROOT_LIBRARIES} PUserFcnBase cuba BMWtools
diff --git a/src/external/mud/src/CMakeLists.txt b/src/external/mud/src/CMakeLists.txt
index c6dd2ab76..8dda07a24 100644
--- a/src/external/mud/src/CMakeLists.txt
+++ b/src/external/mud/src/CMakeLists.txt
@@ -26,9 +26,6 @@ set_target_properties(mud
     VERSION ${MUD_VERSION}
 )
 
-#--- add compile options for optimization -------------------------------------
-target_compile_options(mud PUBLIC -O3)
-
 #--- install mud solib --------------------------------------------------------
 install(TARGETS mud DESTINATION lib) 
 
diff --git a/src/external/nexus/CMakeLists.txt b/src/external/nexus/CMakeLists.txt
index f8d1e02bc..592576ab9 100644
--- a/src/external/nexus/CMakeLists.txt
+++ b/src/external/nexus/CMakeLists.txt
@@ -27,9 +27,6 @@ target_include_directories(
   PNeXus BEFORE PRIVATE $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
 )
 
-#--- add compile options for optimization -------------------------------------
-target_compile_options(PNeXus PUBLIC -O3)
-
 #--- add library dependencies -------------------------------------------------
 target_link_libraries(PNeXus ${NEXUS_LIBRARY})