diff --git a/CMakeLists.txt b/CMakeLists.txt
index 22fdc4316..41dae831e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -82,12 +82,12 @@ if(NOT CMAKE_CONFIGURATION_TYPES AND NOT CMAKE_BUILD_TYPE)
 endif()
 
 
-#
 # Common settings across all projects, dependencies, etc. Always support
-# 64 bit file operations, even 32 bit platforms.
-#
+# 64 bit file operations, even on 32 bit platforms.
 
-add_definitions(-D_FILE_OFFSET_BITS=64)
+if(NOT WIN32)
+	add_definitions(-D_FILE_OFFSET_BITS=64)
+endif()
 
 
 # Modules