diff --git a/codec/CMakeLists.txt b/codec/CMakeLists.txt
index 9e35ea7a..6c33b963 100644
--- a/codec/CMakeLists.txt
+++ b/codec/CMakeLists.txt
@@ -24,6 +24,14 @@ IF(DONT_HAVE_GETOPT)
   )
 ENDIF(DONT_HAVE_GETOPT)
 
+IF(WIN32)
+  IF(BUILD_SHARED_LIBS)
+    ADD_DEFINITIONS(-DOPJ_EXPORTS)
+  ELSE(BUILD_SHARED_LIBS)
+    ADD_DEFINITIONS(-DOPJ_STATIC)
+  ENDIF(BUILD_SHARED_LIBS)
+ENDIF(WIN32)
+
 # Loop over all executables:
 FOREACH(exe jp3d_to_volume volume_to_jp3d)
   ADD_EXECUTABLE(${exe} ${exe}.c ${common_SRCS})