diff --git a/include/fluidsynth.cmake b/include/fluidsynth.cmake
index 021b1cda..654a4fd1 100644
--- a/include/fluidsynth.cmake
+++ b/include/fluidsynth.cmake
@@ -43,6 +43,9 @@ extern "C" {
 #elif defined(MACOS9)
 #define FLUIDSYNTH_API __declspec(export)
 
+#elif defined(__OS2__)
+#define FLUIDSYNTH_API __declspec(dllexport)
+
 #elif defined(__GNUC__)
 #define FLUIDSYNTH_API __attribute__ ((visibility ("default")))