diff --git a/src/xspice/icm/dlmain.c b/src/xspice/icm/dlmain.c
index 496f86020..bdd044f9f 100644
--- a/src/xspice/icm/dlmain.c
+++ b/src/xspice/icm/dlmain.c
@@ -41,10 +41,23 @@ struct coreInfo_t *coreitf;
 // Functions that return pointers to structures.
 //////////////////////////////////////////////////////////////////////////////
 
-#if defined (__MINGW32__) || defined (__CYGWIN__) || defined (_MSC_VER)
+//#if defined (__MINGW32__) || defined (__CYGWIN__) || defined (_MSC_VER)
+//#define CM_EXPORT __declspec(dllexport)
+//#else
+//#define CM_EXPORT
+//#endif
+
+#if defined(__MINGW32__) || defined(_MSC_VER) || defined(__CYGWIN__)
 #define CM_EXPORT __declspec(dllexport)
 #else
-#define CM_EXPORT
+  /* use with gcc flag -fvisibility=hidden */
+  #if __GNUC__ >= 4
+    #define CM_EXPORT __attribute__ ((visibility ("default")))
+    #define CM_EXPORT_LOCAL  __attribute__ ((visibility ("hidden")))
+  #else
+    #define CM_EXPORT
+    #define CM_EXPORT_LOCAL
+  #endif
 #endif
 
 extern CM_EXPORT void *CMdevs(void);