diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 5d909ec..ab7eb6f 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -20,6 +20,7 @@ if (${CMAKE_SOURCE_DIR} STREQUAL ${CMAKE_BINARY_DIR})
   message(FATAL_ERROR "In-source builds not allowed.")
 endif()
 
+if(0)
 # ==============================================================================
 # OpenMVG build options
 # ==============================================================================
@@ -37,6 +38,7 @@ option(OpenMVG_USE_OPENMP "Enable OpenMP parallelization" ON)
 #  and openMVG simultaneously
 # ==============================================================================
 option(OpenMVG_USE_OPENCV "Build or not opencv+openMVG samples programs" OFF)
+endif()
 
 # ==============================================================================
 # Since OpenCV 3, SIFT is no longer in the default modules. See
@@ -95,6 +97,7 @@ if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
   register_definitions(-DOPENMVG_STD_UNORDERED_MAP)
 endif()
 
+if(0)
 # ==============================================================================
 # Check that submodule have been initialized and updated
 # ==============================================================================
@@ -103,6 +106,7 @@ if (NOT EXISTS ${PROJECT_SOURCE_DIR}/dependencies/cereal/include)
     "\n submodule(s) are missing, please update your repository:\n"
     "  > git submodule update -i\n")
 endif()
+endif()
 
 # ==============================================================================
 # Additional cmake find modules
@@ -138,7 +142,6 @@ if (OpenMVG_USE_OPENMP)
   find_package(OpenMP)
   if (OPENMP_FOUND)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}")
-    option(OpenMVG_USE_OPENMP "Use OpenMP for parallelization" ON)
     register_definitions(-DOPENMVG_USE_OPENMP)
     if (NOT MSVC)
       if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
@@ -149,11 +152,6 @@ if (OpenMVG_USE_OPENMP)
       endif()
     endif (NOT MSVC)
   endif (OPENMP_FOUND)
-else (OpenMVG_USE_OPENMP)
-    option(OpenMVG_USE_OPENMP "Use OpenMP for parallelization" OFF)
-    include(UpdateCacheVariable)
-    UPDATE_CACHE_VARIABLE(OpenMVG_USE_OPENMP OFF)
-    remove_definitions(-DOPENMVG_USE_OPENMP)
 endif (OpenMVG_USE_OPENMP)
 
 # ==============================================================================
@@ -170,9 +168,10 @@ endif()
 # ==============================================================================
 # IMAGE IO detection
 # ==============================================================================
-find_package(JPEG QUIET)
-find_package(PNG QUIET)
-find_package(TIFF QUIET)
+find_package(JPEG REQUIRED)
+find_package(PNG REQUIRED)
+find_package(TIFF REQUIRED)
+find_package(vlfeat REQUIRED)
 
 # Folders
 set_property(GLOBAL PROPERTY USE_FOLDERS ON)
@@ -192,6 +191,7 @@ if (OpenMVG_BUILD_OPENGL_EXAMPLES)
   set_property(TARGET glfw PROPERTY FOLDER OpenMVG/3rdParty/glfw)
 endif (OpenMVG_BUILD_OPENGL_EXAMPLES)
 
+if(0)
 # Dependencies install rules
 install(
   DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/dependencies/
@@ -199,6 +199,7 @@ install(
   COMPONENT headers
   FILES_MATCHING PATTERN "*.hpp" PATTERN "*.h"
 )
+endif()
 
 # ==============================================================================
 # --END-- SUBMODULE CONFIGURATION
@@ -235,6 +236,7 @@ ENDMACRO(UNIT_TEST)
 # - external by default
 # - internal if cereal not found
 # ==============================================================================
+if(0)
 find_package(cereal QUIET CONFIG)
 if (NOT TARGET cereal)
   add_library(cereal INTERFACE)
@@ -247,7 +249,11 @@ if (NOT TARGET cereal)
 
   set(OpenMVG_USE_INTERNAL_CEREAL ON)
 endif()
+endif()
 
+find_package(cereal REQUIRED CONFIG)
+get_target_property(CEREAL_INCLUDE_DIRS cereal::cereal INTERFACE_INCLUDE_DIRECTORIES)
+ 
 # ==============================================================================
 # Eigen
 # ==============================================================================
@@ -255,6 +261,7 @@ endif()
 # - external if EIGEN_INCLUDE_DIR_HINTS is defined
 # - internal if Eigen not found
 # ==============================================================================
+if(0)
 find_package(Eigen3 QUIET)
 if (NOT Eigen3_FOUND)
   set(EIGEN_INCLUDE_DIR_HINTS ${CMAKE_CURRENT_SOURCE_DIR}/third_party/eigen)
@@ -263,6 +270,10 @@ if (NOT Eigen3_FOUND)
 else()
   set(EIGEN_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR})
 endif()
+endif()
+ 
+find_package(Eigen3 REQUIRED)
+set(EIGEN_INCLUDE_DIRS ${EIGEN3_INCLUDE_DIR})
 
 # ==============================================================================
 # Ceres
@@ -270,6 +281,7 @@ endif()
 # - external by default if CERES_DIR_HINTS or find_package found a valid Ceres
 # - internal if ceres not found (ceres-solver+cxsparse+miniglog)
 # ==============================================================================
+if(0)
 find_package(Ceres QUIET HINTS ${CERES_DIR_HINTS})
 if (NOT Ceres_FOUND)
   set(OpenMVG_USE_INTERNAL_CERES ON)
@@ -281,6 +293,9 @@ if (NOT Ceres_FOUND)
     STRING(REGEX REPLACE "version ([0-9.]+).*" "\\1" CERES_VERSION ${CERES_CONFIG})
   set(CERES_LIBRARIES openMVG_ceres)
 endif()
+endif()
+ 
+find_package(Ceres REQUIRED)
 
 # ==============================================================================
 # Flann
@@ -288,6 +303,7 @@ endif()
 # - internal by default (flann),
 # - external if FLANN_INCLUDE_DIR_HINTS and a valid Flann setup is found
 # ==============================================================================
+if(0)
 if (NOT DEFINED FLANN_INCLUDE_DIR_HINTS)
   set(FLANN_INCLUDE_DIR_HINTS ${CMAKE_CURRENT_SOURCE_DIR}/third_party/flann/src/cpp)
   set(OpenMVG_USE_INTERNAL_FLANN ON)
@@ -296,6 +312,9 @@ find_package(Flann QUIET)
 if (NOT FLANN_FOUND OR OpenMVG_USE_INTERNAL_FLANN)
   set(FLANN_INCLUDE_DIRS ${CMAKE_CURRENT_SOURCE_DIR}/third_party/flann/src/cpp)
 endif()
+endif()
+ 
+find_package(flann REQUIRED)

 # ==============================================================================
 # CoinUtils
@@ -364,6 +395,7 @@ endif()
 # - internal by default (Lemon),
 # - external if LEMON_INCLUDE_DIR_HINTS and a valid Lemon setup is found
 # ==============================================================================
+if(0)
 if (NOT DEFINED LEMON_INCLUDE_DIR_HINTS)
   set(LEMON_INCLUDE_DIR_HINTS ${CMAKE_CURRENT_SOURCE_DIR}/third_party/lemon)
   set(OpenMVG_USE_INTERNAL_LEMON ON)
@@ -374,6 +406,9 @@ if (NOT LEMON_FOUND OR OpenMVG_USE_INTERNAL_LEMON)
     ${CMAKE_CURRENT_SOURCE_DIR}/third_party/lemon
     ${PROJECT_BINARY_DIR}/third_party/lemon)
 endif()
+endif()
+
+find_package(LEMON REQUIRED)
 
 # ==============================================================================
 # OpenCV
@@ -381,12 +416,7 @@ endif()
 # - only external and enabled only if OpenMVG_USE_OPENCV is set to ON
 # ==============================================================================
 if (OpenMVG_USE_OPENCV)
-  find_package( OpenCV QUIET )
-  if (NOT OpenCV_FOUND OR OpenCV_VERSION VERSION_LESS "3.0.0")
-    message(STATUS "OpenCV was not found (note that OpenCV version >= 3.0.0 is required). -> Disabling OpenCV support.")
-    UPDATE_CACHE_VARIABLE(OpenMVG_USE_OPENCV OFF)
-    UPDATE_CACHE_VARIABLE(OpenMVG_USE_OCVSIFT OFF)
-  endif()
+    find_package( OpenCV REQUIRED )
 endif()
 
 
@@ -394,7 +424,6 @@ endif()
 # Third-party libraries:
 # ==============================================================================
 add_subdirectory(third_party)
-add_subdirectory(testing)
 
 # ==============================================================================
 # openMVG modules
@@ -481,67 +510,67 @@ message("** Use OpenCV SIFT features: " ${OpenMVG_USE_OCVSIFT})
 
 message("\n")
 
-if (DEFINED OpenMVG_USE_INTERNAL_CEREAL)
+if (OpenMVG_USE_INTERNAL_CEREAL)
   message(STATUS "CEREAL: (internal)")
 else()
   message(STATUS "CEREAL: (external)")
 endif()
 
-if (DEFINED OpenMVG_USE_INTERNAL_EIGEN)
+if (OpenMVG_USE_INTERNAL_EIGEN)
   message(STATUS "EIGEN: " ${EIGEN_VERSION} " (internal)")
 else()
   message(STATUS "EIGEN: " ${EIGEN_VERSION} " (external)")
 endif()
 
-if (DEFINED OpenMVG_USE_INTERNAL_CERES)
+if (OpenMVG_USE_INTERNAL_CERES)
   message(STATUS "CERES: " ${CERES_VERSION} " (internal)")
 else()
   message(STATUS "CERES: " ${CERES_VERSION} " (external)")
 endif()
 
-if (DEFINED OpenMVG_USE_INTERNAL_FLANN)
+if (OpenMVG_USE_INTERNAL_FLANN)
   message(STATUS "FLANN: " ${FLANN_VERSION} " (internal)")
 else()
   message(STATUS "FLANN: " ${FLANN_VERSION} " (external)")
 endif()
 
-if (DEFINED OpenMVG_USE_INTERNAL_TIFF)
+if (OpenMVG_USE_INTERNAL_TIFF)
   message(STATUS "LIBTIFF: " ${TIFF_VERSION_STRING} " (internal)")
 else()
   message(STATUS "LIBTIFF: " ${TIFF_VERSION_STRING} " (external)")
 endif()
 
-if (DEFINED OpenMVG_USE_INTERNAL_PNG)
+if (OpenMVG_USE_INTERNAL_PNG)
   message(STATUS "LIBPNG: " ${PNG_VERSION_STRING} " (internal)")
 else()
   message(STATUS "LIBPNG: " ${PNG_VERSION_STRING} " (external)")
 endif()
 
-if (DEFINED OpenMVG_USE_INTERNAL_JPEG)
+if (OpenMVG_USE_INTERNAL_JPEG)
   message(STATUS "LIBJPEG (internal)")
 else()
   message(STATUS "LIBJPEG (external)")
 endif()
 
-if (DEFINED OpenMVG_USE_INTERNAL_CLP)
+if (OpenMVG_USE_INTERNAL_CLP)
   message(STATUS "CLP: " ${CLP_VERSION} " (internal)")
 else()
   message(STATUS "CLP: " ${CLP_VERSION} " (external)")
 endif()
 
-if (DEFINED OpenMVG_USE_INTERNAL_COINUTILS)
+if (OpenMVG_USE_INTERNAL_COINUTILS)
   message(STATUS "COINUTILS: " ${COINUTILS_VERSION} " (internal)")
 else()
   message(STATUS "COINUTILS: " ${COINUTILS_VERSION} " (external)")
 endif()
 
-if (DEFINED OpenMVG_USE_INTERNAL_OSI)
+if (OpenMVG_USE_INTERNAL_OSI)
   message(STATUS "OSI: " ${OSI_VERSION} " (internal)")
 else()
   message(STATUS "OSI: " ${OSI_VERSION} " (external)")
 endif()
 
-if (DEFINED OpenMVG_USE_INTERNAL_LEMON)
+if (OpenMVG_USE_INTERNAL_LEMON)
   message(STATUS "LEMON: " ${LEMON_VERSION} " (internal)")
 else()
   message(STATUS "LEMON: " ${LEMON_VERSION} " (external)")
diff --git a/src/cmakeFindModules/OpenMVGConfig.cmake.in b/src/cmakeFindModules/OpenMVGConfig.cmake.in
index e7dfbfd..65224c4 100644
--- a/src/cmakeFindModules/OpenMVGConfig.cmake.in
+++ b/src/cmakeFindModules/OpenMVGConfig.cmake.in
@@ -19,7 +19,7 @@
 # OPENMVG_VERSION: Version of OpenMVG found.
 #
 
-# Called if we failed to find OpenMVG or any of it's required dependencies,
+# Called if we failed to find OpenMVG or any of its required dependencies,
 # unsets all public (designed to be used externally) variables and reports
 # error message at priority depending upon [REQUIRED/QUIET/<NONE>] argument.
 macro(OPENMVG_REPORT_NOT_FOUND REASON_MSG)
@@ -58,10 +58,17 @@ set(CALLERS_CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH})
 # Reset CMake module path to the installation directory of this
 # script.
 set(CMAKE_MODULE_PATH ${CURRENT_CONFIG_INSTALL_DIR})
+include(CMakeFindDependencyMacro)
+
+find_dependency(flann)
+find_dependency(Threads)
+find_dependency(cereal)
+find_dependency(Ceres)
+find_dependency(vlfeat)
 
 # Build the absolute root install directory as a relative path
 get_filename_component(CURRENT_ROOT_INSTALL_DIR
-  ${CMAKE_MODULE_PATH}/../../../ ABSOLUTE)
+  ${CMAKE_MODULE_PATH}/../../ ABSOLUTE)
 if (NOT EXISTS ${CURRENT_ROOT_INSTALL_DIR})
   OPENMVG_REPORT_NOT_FOUND(
     "OpenMVG install root: ${CURRENT_ROOT_INSTALL_DIR}, "
diff --git a/src/nonFree/sift/CMakeLists.txt b/src/nonFree/sift/CMakeLists.txt
index 402a2d8..60ddc11 100644
--- a/src/nonFree/sift/CMakeLists.txt
+++ b/src/nonFree/sift/CMakeLists.txt
@@ -1,36 +1,36 @@
 
-# libs should be static
-set(BUILD_SHARED_LIBS OFF)
-
-# use PIC code for link into shared lib
-if(UNIX)
-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fPIC")
-endif(UNIX)
-
-if(NOT USE_SSE2)
-  add_definitions(-DVL_DISABLE_SSE2)
-endif()
-
-add_definitions(-DVL_DISABLE_THREADS)
-
-include_directories(./vl)
-set(FEATS
-  vl/generic.c
-  vl/imopv_sse2.c
-  vl/sift.c
-  vl/imopv.c
-  vl/mathop_sse2.c
-  vl/sift.c
-  vl/host.c
-  vl/mathop.c
-  vl/random.c)
-set_source_files_properties(${FEATS} PROPERTIES LANGUAGE C)
-add_library(vlsift ${FEATS})
-install(TARGETS vlsift DESTINATION lib EXPORT openMVG-targets)
-set_property(TARGET vlsift PROPERTY FOLDER OpenMVG/nonFree)
+## libs should be static
+#set(BUILD_SHARED_LIBS OFF)
+#
+## use PIC code for link into shared lib
+#if(UNIX)
+#  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fPIC")
+#endif(UNIX)
+#
+#if(NOT USE_SSE2)
+#  add_definitions(-DVL_DISABLE_SSE2)
+#endif()
+#
+#add_definitions(-DVL_DISABLE_THREADS)
+#
+#include_directories(./vl)
+#set(FEATS
+#  vl/generic.c
+#  vl/imopv_sse2.c
+#  vl/sift.c
+#  vl/imopv.c
+#  vl/mathop_sse2.c
+#  vl/sift.c
+#  vl/host.c
+#  vl/mathop.c
+#  vl/random.c)
+#set_source_files_properties(${FEATS} PROPERTIES LANGUAGE C)
+#add_library(vlsift ${FEATS})
+#install(TARGETS vlsift DESTINATION lib EXPORT openMVG-targets)
+#set_property(TARGET vlsift PROPERTY FOLDER OpenMVG/nonFree)
 install(
   DIRECTORY .
   DESTINATION include/openMVG_dependencies/nonFree/sift
   COMPONENT headers
-  FILES_MATCHING PATTERN "*.hpp" PATTERN "*.h"
+  FILES_MATCHING PATTERN "*.hpp"
 )
diff --git a/src/nonFree/sift/SIFT_describer.hpp b/src/nonFree/sift/SIFT_describer.hpp
index cd800b0..20e9c8e 100644
--- a/src/nonFree/sift/SIFT_describer.hpp
+++ b/src/nonFree/sift/SIFT_describer.hpp
@@ -17,9 +17,7 @@
 #include <iostream>
 #include <numeric>
 
-extern "C" {
-#include "nonFree/sift/vl/sift.h"
-}
+#include <sift.h>
 
 namespace openMVG {
 namespace features {
@@ -174,7 +172,7 @@ public:
       const int nkeys = vl_sift_get_nkeypoints(filt);
 
       // Update gradient before launching parallel extraction
-      vl_sift_update_gradient(filt);
+      update_gradient(filt);
 
       #ifdef OPENMVG_USE_OPENMP
       #pragma omp parallel for private(descr, descriptor)
diff --git a/src/openMVG/matching/CMakeLists.txt b/src/openMVG/matching/CMakeLists.txt
index 2e0eafd7..d54d1e88 100644
--- a/src/openMVG/matching/CMakeLists.txt
+++ b/src/openMVG/matching/CMakeLists.txt
@@ -16,6 +16,7 @@ list(REMOVE_ITEM matching_files_cpp ${REMOVEFILESUNITTEST})
 
 set(THREADS_PREFER_PTHREAD_FLAG ON)
 find_package(Threads REQUIRED)
+find_package(flann CONFIG REQUIRED)
 
 set_source_files_properties(${matching_files_cpp} PROPERTIES LANGUAGE CXX)
 add_library(openMVG_matching
@@ -35,12 +36,12 @@ target_link_libraries(openMVG_matching
   PUBLIC
     openMVG_features
     Threads::Threads
-    cereal
+    cereal::cereal
 )
-if (NOT DEFINED OpenMVG_USE_INTERNAL_FLANN)
+if (NOT OpenMVG_USE_INTERNAL_FLANN)
 target_link_libraries(openMVG_matching
   PUBLIC
-    ${FLANN_LIBRARIES}
+    $<IF:$<TARGET_EXISTS:flann::flann_s>,flann::flann_s,flann::flann>
 )
 endif()
 set_target_properties(openMVG_matching PROPERTIES SOVERSION ${OPENMVG_VERSION_MAJOR} VERSION "${OPENMVG_VERSION_MAJOR}.${OPENMVG_VERSION_MINOR}")
diff --git a/src/openMVG/numeric/CMakeLists.txt b/src/openMVG/numeric/CMakeLists.txt
index 1f3fc30..4097320 100644
--- a/src/openMVG/numeric/CMakeLists.txt
+++ b/src/openMVG/numeric/CMakeLists.txt
@@ -26,7 +26,7 @@ target_include_directories(openMVG_numeric
     $<BUILD_INTERFACE:${CMAKE_SOURCE_DIR}>
     $<INSTALL_INTERFACE:include>
 )
-if (DEFINED OpenMVG_USE_INTERNAL_EIGEN)
+if (OpenMVG_USE_INTERNAL_EIGEN)
   target_include_directories(openMVG_numeric PUBLIC
     $<INSTALL_INTERFACE:${CMAKE_INSTALL_PREFIX}/include/openMVG/third_party/eigen/>)
 else()
diff --git a/src/openMVG_Samples/describe_and_match_GUI/CMakeLists.txt b/src/openMVG_Samples/describe_and_match_GUI/CMakeLists.txt
index 862ffc7..62508af 100644
--- a/src/openMVG_Samples/describe_and_match_GUI/CMakeLists.txt
+++ b/src/openMVG_Samples/describe_and_match_GUI/CMakeLists.txt
@@ -18,8 +18,7 @@ if (OpenMVG_BUILD_GUI_SOFTWARES)
       add_executable( openMVG_sample_describe_and_match_GUI WIN32 ${FEATURES_PAIR_DEMO_SRCS} ${FEATURES_PAIR_DEMO_HDRS} )
     endif( APPLE )
 
-    target_link_libraries( openMVG_sample_describe_and_match_GUI Qt5::Widgets openMVG_features openMVG_image openMVG_matching vlsift )
-
+    target_link_libraries( openMVG_sample_describe_and_match_GUI Qt5::Widgets openMVG_features openMVG_image openMVG_matching unofficial::vlfeat::vl )
     set_target_properties( openMVG_sample_describe_and_match_GUI PROPERTIES CXX_STANDARD 11)
 
     set_property(TARGET openMVG_sample_describe_and_match_GUI PROPERTY FOLDER OpenMVG/Samples)
diff --git a/src/openMVG_Samples/features_image_matching/CMakeLists.txt b/src/openMVG_Samples/features_image_matching/CMakeLists.txt
index 18fb385..d44ffce 100644
--- a/src/openMVG_Samples/features_image_matching/CMakeLists.txt
+++ b/src/openMVG_Samples/features_image_matching/CMakeLists.txt
@@ -5,7 +5,7 @@ target_link_libraries(openMVG_sample_image_matching
   openMVG_features
   openMVG_matching
   ${STLPLUS_LIBRARY}
-  vlsift)
+  unofficial::vlfeat::vl)
 target_compile_definitions(openMVG_sample_image_matching
   PRIVATE -DTHIS_SOURCE_DIR="${CMAKE_CURRENT_SOURCE_DIR}")
 
diff --git a/src/openMVG_Samples/features_repeatability/CMakeLists.txt b/src/openMVG_Samples/features_repeatability/CMakeLists.txt
index fd2b7c6..91f2766 100644
--- a/src/openMVG_Samples/features_repeatability/CMakeLists.txt
+++ b/src/openMVG_Samples/features_repeatability/CMakeLists.txt
@@ -6,7 +6,7 @@ target_link_libraries(openMVG_sample_main_features_repeatability_dataset
   openMVG_matching
   openMVG_system
   openMVG_multiview
-  vlsift
+  unofficial::vlfeat::vl
   ${STLPLUS_LIBRARY})
 
 set_property(TARGET openMVG_sample_main_features_repeatability_dataset PROPERTY FOLDER OpenMVG/Samples)
diff --git a/src/software/Localization/CMakeLists.txt b/src/software/Localization/CMakeLists.txt
index 2f60393..0d57d0a 100644
--- a/src/software/Localization/CMakeLists.txt
+++ b/src/software/Localization/CMakeLists.txt
@@ -11,7 +11,7 @@ target_link_libraries(openMVG_main_SfM_Localization
   openMVG_sfm
   openMVG_exif
   ${STLPLUS_LIBRARY}
-  vlsift
+  unofficial::vlfeat::vl
   )
 
 # Installation rules
diff --git a/src/software/SfM/CMakeLists.txt b/src/software/SfM/CMakeLists.txt
index 6db7e83..51e06f5 100644
--- a/src/software/SfM/CMakeLists.txt
+++ b/src/software/SfM/CMakeLists.txt
@@ -44,7 +44,7 @@ target_link_libraries(openMVG_main_ComputeFeatures
     openMVG_multiview
     openMVG_sfm
     ${STLPLUS_LIBRARY}
-    vlsift
+    unofficial::vlfeat::vl
 )
 if (MSVC)
   set_target_properties(openMVG_main_ComputeFeatures PROPERTIES COMPILE_FLAGS "/bigobj")
@@ -275,7 +275,7 @@ if(OpenMVG_USE_OPENCV)
     openMVG_multiview
     openMVG_sfm
     ${STLPLUS_LIBRARY}
-    vlsift
+    unofficial::vlfeat::vl
     ${OpenCV_LIBS})
   target_include_directories(openMVG_main_ComputeFeatures_OpenCV PRIVATE ${OpenCV_INCLUDE_DIRS})
 
diff --git a/src/software/VO/Tracker_opencv_klt.hpp b/src/software/VO/Tracker_opencv_klt.hpp
index aa7dffe..2c4d237 100644
--- a/src/software/VO/Tracker_opencv_klt.hpp
+++ b/src/software/VO/Tracker_opencv_klt.hpp
@@ -80,7 +80,7 @@ struct Tracker_opencv_KLT : public Abstract_Tracker
     std::vector<cv::KeyPoint> m_nextKeypoints;
 
     cv::Ptr<cv::FeatureDetector> m_detector = cv::GFTTDetector::create(count);
-    if (m_detector == NULL)
+    if (m_detector == nullptr)
       return false;
 
     m_detector->detect(current_img, m_nextKeypoints);
diff --git a/src/third_party/CMakeLists.txt b/src/third_party/CMakeLists.txt
index 0d61c9f..05c8b29 100644
--- a/src/third_party/CMakeLists.txt
+++ b/src/third_party/CMakeLists.txt
@@ -18,7 +18,7 @@ add_subdirectory(stlplus3)
 set(STLPLUS_LIBRARY openMVG_stlplus PARENT_SCOPE)
 
 # Add graph library
-if(DEFINED OpenMVG_USE_INTERNAL_LEMON)
+if(OpenMVG_USE_INTERNAL_LEMON)
   add_subdirectory(lemon)
   set(LEMON_LIBRARY openMVG_lemon PARENT_SCOPE)
 endif()
@@ -67,7 +67,7 @@ endif (NOT TIFF_FOUND)
 add_subdirectory(vectorGraphics)
 
 # Add ceres-solver (A Nonlinear Least Squares Minimizer)
-if (DEFINED OpenMVG_USE_INTERNAL_CERES)
+if (OpenMVG_USE_INTERNAL_CERES)
   add_subdirectory(cxsparse)
   add_subdirectory(ceres-solver)
   set_property(TARGET openMVG_cxsparse PROPERTY FOLDER OpenMVG/3rdParty/ceres)
@@ -75,7 +75,7 @@ if (DEFINED OpenMVG_USE_INTERNAL_CERES)
 endif()
 
 # Add an Approximate Nearest Neighbor library
-if (DEFINED OpenMVG_USE_INTERNAL_FLANN)
+if (OpenMVG_USE_INTERNAL_FLANN)
   set(FLANN_INCLUDE_INSTALL_DIR ${CMAKE_INSTALL_PREFIX}/include/openMVG/third_party/flann/src/cpp)
   add_subdirectory(flann)
 endif()
@@ -89,7 +89,7 @@ add_subdirectory(fast)
 ##
 # Install Header only libraries if necessary
 ##
-if (DEFINED OpenMVG_USE_INTERNAL_EIGEN)
+if (OpenMVG_USE_INTERNAL_EIGEN)
   #Configure Eigen install
   set(INCLUDE_INSTALL_DIR ${CMAKE_INSTALL_PREFIX}/include/openMVG/third_party/eigen)
   add_subdirectory(eigen)
diff --git a/src/openMVG/cameras/CMakeLists.txt b/src/openMVG/cameras/CMakeLists.txt
index 333ab729..50c8f572 100644
--- a/src/openMVG/cameras/CMakeLists.txt
+++ b/src/openMVG/cameras/CMakeLists.txt
@@ -4,7 +4,7 @@ set_property(TARGET openMVG_camera APPEND PROPERTY
   INTERFACE_INCLUDE_DIRECTORIES "$<INSTALL_INTERFACE:include>")
 
 target_compile_features(openMVG_camera INTERFACE ${CXX11_FEATURES})
-target_link_libraries(openMVG_camera INTERFACE openMVG_numeric cereal ${OPENMVG_LIBRARY_DEPENDENCIES})
+target_link_libraries(openMVG_camera INTERFACE openMVG_numeric cereal::cereal ${OPENMVG_LIBRARY_DEPENDENCIES})
 install(TARGETS openMVG_camera DESTINATION lib EXPORT openMVG-targets)
 
 UNIT_TEST(openMVG Camera_Pinhole openMVG_camera)
diff --git a/src/openMVG/features/CMakeLists.txt b/src/openMVG/features/CMakeLists.txt
index 2e49701d..0b5e1c3d 100644
--- a/src/openMVG/features/CMakeLists.txt
+++ b/src/openMVG/features/CMakeLists.txt
@@ -31,7 +31,7 @@ target_include_directories(openMVG_features
 )
 target_link_libraries(openMVG_features
   PRIVATE openMVG_fast ${STLPLUS_LIBRARY}
-  PUBLIC ${OPENMVG_LIBRARY_DEPENDENCIES} cereal)
+  PUBLIC ${OPENMVG_LIBRARY_DEPENDENCIES} cereal::cereal)
 if (MSVC)
   set_target_properties(openMVG_features PROPERTIES COMPILE_FLAGS "/bigobj")
   target_compile_options(openMVG_features PUBLIC "-D_USE_MATH_DEFINES")
diff --git a/src/openMVG/geometry/CMakeLists.txt b/src/openMVG/geometry/CMakeLists.txt
index 0a6a016a..e509a4d5 100644
--- a/src/openMVG/geometry/CMakeLists.txt
+++ b/src/openMVG/geometry/CMakeLists.txt
@@ -21,7 +21,7 @@ set_property(TARGET openMVG_geometry PROPERTY FOLDER OpenMVG/OpenMVG)
 target_link_libraries(openMVG_geometry
   PUBLIC
     openMVG_numeric
-    cereal
+    cereal::cereal
   PRIVATE
     openMVG_linearProgramming
 )
diff --git a/src/openMVG/sfm/CMakeLists.txt b/src/openMVG/sfm/CMakeLists.txt
index b8928083..1d10f939 100644
--- a/src/openMVG/sfm/CMakeLists.txt
+++ b/src/openMVG/sfm/CMakeLists.txt
@@ -25,7 +25,7 @@ target_link_libraries(openMVG_sfm
     openMVG_graph
     openMVG_matching
     openMVG_multiview
-    cereal
+    cereal::cereal
     ${OPENMVG_LIBRARY_DEPENDENCIES}
 )
 
diff --git a/src/cmakeFindModules/FindClp.cmake b/src/cmakeFindModules/FindClp.cmake
index 8a69c2344..1ed9a21fe 100644
--- a/src/cmakeFindModules/FindClp.cmake
+++ b/src/cmakeFindModules/FindClp.cmake
@@ -51,7 +51,7 @@ IF(EXISTS "${CLP_DIR}" AND NOT "${CLP_DIR}" STREQUAL "")
         SET(CLP_INCLUDE_DIR ${CLP_DIR})
 
         FIND_LIBRARY(CLP_LIBRARY NAMES Clp)
-        FIND_LIBRARY(CLPSOLVER_LIBRARY NAMES ClpSolver)
+        FIND_LIBRARY(CLPSOLVER_LIBRARY NAMES ClpSolver Clp)
         FIND_LIBRARY(OSICLP_LIBRARY NAMES OsiClp)
 
         # locate Clp libraries