diff --git a/thirdparty/ffs/ffs/cod/cod.h b/thirdparty/ffs/ffs/cod/cod.h
index 0a866ea8e8..cb1dffb87b 100644
--- a/thirdparty/ffs/ffs/cod/cod.h
+++ b/thirdparty/ffs/ffs/cod/cod.h
@@ -7,8 +7,12 @@ extern "C" {
 #endif
 
 #ifndef FFS_DECL_SPEC
-#if defined(_MSC_VER) && !defined(FFS_SRC)
-#define FFS_DECLSPEC    __declspec(dllimport)
+#if defined(_MSC_VER)
+#if defined(FFS_SRC)
+#define FFS_DECLSPEC __declspec(dllexport)
+#else
+#define FFS_DECLSPEC __declspec(dllimport)
+#endif
 #else
 #define FFS_DECLSPEC
 #endif
diff --git a/thirdparty/ffs/ffs/fm/fm.h b/thirdparty/ffs/ffs/fm/fm.h
index cba86f288a..8dc7d669b0 100755
--- a/thirdparty/ffs/ffs/fm/fm.h
+++ b/thirdparty/ffs/ffs/fm/fm.h
@@ -9,11 +9,17 @@ extern "C" {
 
 typedef struct _FMContextStruct *FMContext;
 
-#if defined(_MSC_VER) && !defined(FFS_SRC)
-#define FFS_DECLSPEC    __declspec(dllimport)
+#ifndef FFS_DECL_SPEC
+#if defined(_MSC_VER)
+#if defined(FFS_SRC)
+#define FFS_DECLSPEC __declspec(dllexport)
+#else
+#define FFS_DECLSPEC __declspec(dllimport)
+#endif
 #else
 #define FFS_DECLSPEC
 #endif
+#endif
 
 extern FFS_DECLSPEC FMContext create_FMcontext();
 extern FFS_DECLSPEC FMContext create_local_FMcontext();