diff --git a/CMakeLists.txt b/CMakeLists.txt
index 296456d..5754726 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -58,9 +58,11 @@
    message(FATAL_ERROR "Option ${USE_SIMD} not supported, valid entries are ${USE_SIMD_VALUES}")
  ENDIF()
 
-IF(CMAKE_CXX_COMPILER MATCHES ".*clang")
+ SET(CMAKE_COMPILER_IS_CLANGXX 0)
+IF(CMAKE_CXX_COMPILER MATCHES "Clang")
     SET(CMAKE_COMPILER_IS_CLANGXX 1)
 ENDIF()
+MESSAGE(STATUS "CMAKE_COMPILER_IS_CLANGXX is '${CMAKE_COMPILER_IS_CLANGXX}'")
 
 IF(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_COMPILER_IS_CLANGXX)
     ADD_DEFINITIONS(-Wall)
@@ -182,9 +184,11 @@
 ########################################################################
 # Setup the include and linker paths
 ########################################################################
-include_directories(
+include_directories(BEFORE
     ${CMAKE_SOURCE_DIR}/include
     ${CMAKE_SOURCE_DIR}/lib
+)
+include_directories(AFTER
     ${Boost_INCLUDE_DIRS}
     ${GNURADIO_ALL_INCLUDE_DIRS}
 )
diff --git a/cmake/Modules/GrSwig.cmake b/cmake/Modules/GrSwig.cmake
index f907a51..a219352 100644
--- a/cmake/Modules/GrSwig.cmake
+++ b/cmake/Modules/GrSwig.cmake
@@ -156,7 +156,7 @@
     )
 
     #append the specified include directories
-    include_directories(${GR_SWIG_INCLUDE_DIRS})
+    include_directories(AFTER ${GR_SWIG_INCLUDE_DIRS})
     list(APPEND SWIG_MODULE_${name}_EXTRA_DEPS ${tag_file})
 
     #setup the swig flags with flags and include directories
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index 4f83f72..65932ab 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -121,7 +121,7 @@
 GR_REGISTER_COMPONENT("Osmocom IQ Imbalance Correction" ENABLE_IQBALANCE GNURADIO_IQBALANCE_FOUND)
 if(ENABLE_IQBALANCE)
 add_definitions(-DHAVE_IQBALANCE=1)
-include_directories(${GNURADIO_IQBALANCE_INCLUDE_DIRS})
+include_directories(AFTER ${GNURADIO_IQBALANCE_INCLUDE_DIRS})
 GR_OSMOSDR_APPEND_LIBS(${GNURADIO_IQBALANCE_LIBRARIES})
 endif(ENABLE_IQBALANCE)
 
diff --git a/lib/airspy/CMakeLists.txt b/lib/airspy/CMakeLists.txt
index 3e34aa6..52b0c31 100644
--- a/lib/airspy/CMakeLists.txt
+++ b/lib/airspy/CMakeLists.txt
@@ -21,8 +21,10 @@
 # This file included, use CMake directory variables
 ########################################################################
 
-include_directories(
+include_directories(BEFORE
     ${CMAKE_CURRENT_SOURCE_DIR}
+)
+include_directories(AFTER
     ${LIBAIRSPY_INCLUDE_DIRS}
 )
 
diff --git a/lib/bladerf/CMakeLists.txt b/lib/bladerf/CMakeLists.txt
index c253a22..026c57f 100644
--- a/lib/bladerf/CMakeLists.txt
+++ b/lib/bladerf/CMakeLists.txt
@@ -21,8 +21,10 @@
 # This file included, use CMake directory variables
 ########################################################################
 
-include_directories(
+include_directories(BEFORE
     ${CMAKE_CURRENT_SOURCE_DIR}
+)
+include_directories(AFTER
     ${LIBBLADERF_INCLUDE_DIRS}
     ${VOLK_INCLUDE_DIRS}
 )
diff --git a/lib/fcd/CMakeLists.txt b/lib/fcd/CMakeLists.txt
index e71b153..3c2bfa6 100644
--- a/lib/fcd/CMakeLists.txt
+++ b/lib/fcd/CMakeLists.txt
@@ -21,14 +21,14 @@
 # This file included, use CMake directory variables
 ########################################################################
 
-include_directories(${CMAKE_CURRENT_SOURCE_DIR})
+include_directories(BEFORE ${CMAKE_CURRENT_SOURCE_DIR})
 
 if(ENABLE_FCD)
-include_directories(${GNURADIO_FCD_INCLUDE_DIRS})
+include_directories(AFTER ${GNURADIO_FCD_INCLUDE_DIRS})
 endif(ENABLE_FCD)
 
 if(ENABLE_FCDPP)
-include_directories(${GNURADIO_FCDPP_INCLUDE_DIRS})
+include_directories(AFTER ${GNURADIO_FCDPP_INCLUDE_DIRS})
 endif(ENABLE_FCDPP)
 
 set(fcd_srcs
diff --git a/lib/file/CMakeLists.txt b/lib/file/CMakeLists.txt
index 6c55e85..0bae0b4 100644
--- a/lib/file/CMakeLists.txt
+++ b/lib/file/CMakeLists.txt
@@ -21,7 +21,7 @@
 # This file included, use CMake directory variables
 ########################################################################
 
-include_directories(
+include_directories(BEFORE
     ${CMAKE_CURRENT_SOURCE_DIR}
 )
 
diff --git a/lib/freesrp/CMakeLists.txt b/lib/freesrp/CMakeLists.txt
index 46df7e4..5cedc4d 100644
--- a/lib/freesrp/CMakeLists.txt
+++ b/lib/freesrp/CMakeLists.txt
@@ -21,8 +21,10 @@
 # This file included, use CMake directory variables
 ########################################################################
 
-include_directories(
+include_directories(BEFORE
     ${CMAKE_CURRENT_SOURCE_DIR}
+)
+include_directories(AFTER
     ${LIBFREESRP_INCLUDE_DIRS}
 )
 
diff --git a/lib/hackrf/CMakeLists.txt b/lib/hackrf/CMakeLists.txt
index c7af0c9..397186a 100644
--- a/lib/hackrf/CMakeLists.txt
+++ b/lib/hackrf/CMakeLists.txt
@@ -21,8 +21,10 @@
 # This file included, use CMake directory variables
 ########################################################################
 
-include_directories(
+include_directories(BEFORE
     ${CMAKE_CURRENT_SOURCE_DIR}
+)
+include_directories(AFTER
     ${LIBHACKRF_INCLUDE_DIRS}
 )
 
diff --git a/lib/miri/CMakeLists.txt b/lib/miri/CMakeLists.txt
index ddaeb0a..8d41565 100644
--- a/lib/miri/CMakeLists.txt
+++ b/lib/miri/CMakeLists.txt
@@ -21,8 +21,10 @@
 # This file included, use CMake directory variables
 ########################################################################
 
-include_directories(
+include_directories(BEFORE
     ${CMAKE_CURRENT_SOURCE_DIR}
+)
+include_directories(AFTER
     ${LIBMIRISDR_INCLUDE_DIRS}
 )
 
diff --git a/lib/osmosdr/CMakeLists.txt b/lib/osmosdr/CMakeLists.txt
index b0872f8..73714ed 100644
--- a/lib/osmosdr/CMakeLists.txt
+++ b/lib/osmosdr/CMakeLists.txt
@@ -21,8 +21,10 @@
 # This file included, use CMake directory variables
 ########################################################################
 
-include_directories(
+include_directories(BEFORE
     ${CMAKE_CURRENT_SOURCE_DIR}
+)
+include_directories(AFTER
     ${LIBOSMOSDR_INCLUDE_DIRS}
 )
 
diff --git a/lib/redpitaya/CMakeLists.txt b/lib/redpitaya/CMakeLists.txt
index a14dc9e..64ffc35 100644
--- a/lib/redpitaya/CMakeLists.txt
+++ b/lib/redpitaya/CMakeLists.txt
@@ -21,7 +21,7 @@
 # This file included, use CMake directory variables
 ########################################################################
 
-include_directories(
+include_directories(BEFORE
     ${CMAKE_CURRENT_SOURCE_DIR}
 )
 
diff --git a/lib/rfspace/CMakeLists.txt b/lib/rfspace/CMakeLists.txt
index eebc15d..f5b9ebe 100644
--- a/lib/rfspace/CMakeLists.txt
+++ b/lib/rfspace/CMakeLists.txt
@@ -21,7 +21,7 @@
 # This file included, use CMake directory variables
 ########################################################################
 
-include_directories(
+include_directories(BEFORE
     ${CMAKE_CURRENT_SOURCE_DIR}
 )
 
diff --git a/lib/rtl/CMakeLists.txt b/lib/rtl/CMakeLists.txt
index f438df5..053b0da 100644
--- a/lib/rtl/CMakeLists.txt
+++ b/lib/rtl/CMakeLists.txt
@@ -21,8 +21,10 @@
 # This file included, use CMake directory variables
 ########################################################################
 
-include_directories(
+include_directories(BEFORE
     ${CMAKE_CURRENT_SOURCE_DIR}
+)
+include_directories(AFTER
     ${LIBRTLSDR_INCLUDE_DIRS}
 )
 
diff --git a/lib/rtl_tcp/CMakeLists.txt b/lib/rtl_tcp/CMakeLists.txt
index 9f7c201..1010304 100644
--- a/lib/rtl_tcp/CMakeLists.txt
+++ b/lib/rtl_tcp/CMakeLists.txt
@@ -21,7 +21,7 @@
 # This file included, use CMake directory variables
 ########################################################################
 
-include_directories(
+include_directories(BEFORE
     ${CMAKE_CURRENT_SOURCE_DIR}
 )
 
diff --git a/lib/sdrplay/CMakeLists.txt b/lib/sdrplay/CMakeLists.txt
index 382ab33..2a468b6 100644
--- a/lib/sdrplay/CMakeLists.txt
+++ b/lib/sdrplay/CMakeLists.txt
@@ -21,8 +21,10 @@
 # This file included, use CMake directory variables
 ########################################################################
 
-include_directories(
+include_directories(BEFORE
     ${CMAKE_CURRENT_SOURCE_DIR}
+)
+include_directories(AFTER
     ${LIBSDRPLAY_INCLUDE_DIRS}
 )
 
diff --git a/lib/soapy/CMakeLists.txt b/lib/soapy/CMakeLists.txt
index 338bcaf..c639d2e 100644
--- a/lib/soapy/CMakeLists.txt
+++ b/lib/soapy/CMakeLists.txt
@@ -21,8 +21,10 @@
 # This file included, use CMake directory variables
 ########################################################################
 
-include_directories(
+include_directories(BEFORE
     ${CMAKE_CURRENT_SOURCE_DIR}
+)
+include_directories(AFTER
     ${SoapySDR_INCLUDE_DIRS}
 )
 
diff --git a/lib/uhd/CMakeLists.txt b/lib/uhd/CMakeLists.txt
index aba5c77..c2539ca 100644
--- a/lib/uhd/CMakeLists.txt
+++ b/lib/uhd/CMakeLists.txt
@@ -21,8 +21,10 @@
 # This file included, use CMake directory variables
 ########################################################################
 
-include_directories(
+include_directories(BEFORE
     ${CMAKE_CURRENT_SOURCE_DIR}
+)
+include_directories(AFTER
     ${GNURADIO_UHD_INCLUDE_DIRS}
     ${UHD_INCLUDE_DIRS}
 )