--- a/Resources/CMake/Compiler.cmake	Mon Aug 21 15:04:20 2017 +0200
+++ b/Resources/CMake/Compiler.cmake	Mon Aug 21 16:28:53 2017 +0200
@@ -57,11 +57,27 @@
 endif()
 
 
+if (${CMAKE_SYSTEM_NAME} STREQUAL "FreeBSD" OR
+    ${CMAKE_SYSTEM_NAME} STREQUAL "OpenBSD")
+  # In FreeBSD/OpenBSD, the "/usr/local/" folder contains the ports and need to be imported
+  SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -I/usr/local/include")
+  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -I/usr/local/include")
+  SET(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -L/usr/local/lib")
+  SET(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -L/usr/local/lib")
+endif()
+
+
 if (${CMAKE_SYSTEM_NAME} STREQUAL "Linux" OR
     ${CMAKE_SYSTEM_NAME} STREQUAL "kFreeBSD" OR
-    ${CMAKE_SYSTEM_NAME} STREQUAL "FreeBSD")
-  set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,--no-undefined")
-  set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,--no-undefined")
+    ${CMAKE_SYSTEM_NAME} STREQUAL "FreeBSD" OR
+    ${CMAKE_SYSTEM_NAME} STREQUAL "OpenBSD")
+
+  if (NOT ${CMAKE_SYSTEM_NAME} STREQUAL "OpenBSD")
+    # The "--no-undefined" linker flag makes the shared libraries
+    # (plugins ModalityWorklists and ServeFolders) fail to compile on OpenBSD
+    set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,--no-undefined")
+    set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,--no-undefined")
+  endif()
 
   if (NOT DEFINED ENABLE_PLUGINS_VERSION_SCRIPT OR 
       ENABLE_PLUGINS_VERSION_SCRIPT)
@@ -71,22 +87,39 @@
   # Remove the "-rdynamic" option
   # http://www.mail-archive.com/cmake@cmake.org/msg08837.html
   set(CMAKE_SHARED_LIBRARY_LINK_CXX_FLAGS "")
-  link_libraries(uuid pthread rt)
+  link_libraries(uuid pthread)
+
+  if (NOT ${CMAKE_SYSTEM_NAME} STREQUAL "OpenBSD")
+    link_libraries(rt)
+  endif()
+
+  if (NOT ${CMAKE_SYSTEM_NAME} STREQUAL "FreeBSD" AND
+      NOT ${CMAKE_SYSTEM_NAME} STREQUAL "OpenBSD")
+    link_libraries(dl)
+  endif()
 
   if (NOT ${CMAKE_SYSTEM_NAME} STREQUAL "FreeBSD")
+    # The "--as-needed" linker flag is not available on FreeBSD
     set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--as-needed")
     set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} -Wl,--as-needed")
     set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,--as-needed")
+  endif()
+
+  if (NOT ${CMAKE_SYSTEM_NAME} STREQUAL "FreeBSD" AND
+      NOT ${CMAKE_SYSTEM_NAME} STREQUAL "OpenBSD")
+    # FreeBSD/OpenBSD have just one single interface for file
+    # handling, which is 64bit clean, so there is no need to define macro
+    # for LFS (Large File Support).
+    # https://ohse.de/uwe/articles/lfs.html
     add_definitions(
       -D_LARGEFILE64_SOURCE=1 
       -D_FILE_OFFSET_BITS=64
       )
-    link_libraries(dl)
   endif()
 
   CHECK_INCLUDE_FILES(uuid/uuid.h HAVE_UUID_H)
   if (NOT HAVE_UUID_H)
-    message(FATAL_ERROR "Please install the uuid-dev package")
+    message(FATAL_ERROR "Please install the uuid-dev package (or e2fsprogs if OpenBSD)")
   endif()
 
 elseif(${CMAKE_SYSTEM_NAME} STREQUAL "Windows")
@@ -146,6 +179,8 @@
     message(FATAL_ERROR "Please install the uuid-dev package")
   endif()
 
+else()
+  message(FATAL_ERROR "Support your platform here")
 endif()
 
 
@@ -156,15 +191,6 @@
 endif()
 
 
-if (${CMAKE_SYSTEM_NAME} STREQUAL "FreeBSD")
-  # In FreeBSD, the "/usr/local/" folder contains the ports and need to be imported
-  SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -I/usr/local/include")
-  SET(CMAKE_CXX_FLAGS "${CMAKE_C_FLAGS} -I/usr/local/include")
-  SET(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -L/usr/local/lib")
-  SET(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -L/usr/local/lib")
-endif()
-
-
 if (DEFINED ENABLE_PROFILING AND ENABLE_PROFILING)
   if (NOT CMAKE_BUILD_TYPE STREQUAL "Debug")
     message(WARNING "Enabling profiling on a non-debug build will not produce full information")