diff --git a/Framework/Kernel/inc/MantidKernel/ANN/ANN.h b/Framework/Kernel/inc/MantidKernel/ANN/ANN.h
index 84db71c5ad26fca32c60c5a0d43329d327270631..736b93c7db634a6222de045bab983f6382a8164f 100644
--- a/Framework/Kernel/inc/MantidKernel/ANN/ANN.h
+++ b/Framework/Kernel/inc/MantidKernel/ANN/ANN.h
@@ -96,9 +96,12 @@
 #else
 #define DLL_API __declspec(dllimport)
 #endif
-//----------------------------------------------------------------------
-// DLL_API is ignored for all other systems
-//----------------------------------------------------------------------
+#elif defined(__GNUC__)
+#ifdef IN_MANTID_KERNEL
+#define DLL_API __attribute__ ((visibility ("default")))
+#else
+#define DLL_API
+#endif
 #else
 #define DLL_API
 #endif