diff --git a/CMakeLists.txt b/CMakeLists.txt
index b2947afce..c3c93d728 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -229,8 +229,8 @@ if(MSVC)
 	endif()
 endif()
 
-# Enable 64bit file support on linux.
-if("${CMAKE_SYSTEM_NAME}" MATCHES "Linux")
+# Enable 64bit file support on linux and FreeBSD.
+if("${CMAKE_SYSTEM_NAME}" MATCHES "Linux" OR FREEBSD)
 	add_definitions("-D_FILE_OFFSET_BITS=64")
 endif()
 
diff --git a/winpr/CMakeLists.txt b/winpr/CMakeLists.txt
index e56b3ad37..0cc7a6e48 100644
--- a/winpr/CMakeLists.txt
+++ b/winpr/CMakeLists.txt
@@ -160,8 +160,8 @@ endif()
 
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DWINPR_EXPORTS")
 
-# Enable 64bit file support on linux.
-if("${CMAKE_SYSTEM_NAME}" MATCHES "Linux")
+# Enable 64bit file support on linux and FreeBSD.
+if("${CMAKE_SYSTEM_NAME}" MATCHES "Linux" OR FREEBSD)
 	add_definitions("-D_FILE_OFFSET_BITS=64")
 endif()