diff --git a/ompi/mca/common/mx/common_mx.h b/ompi/mca/common/mx/common_mx.h
index 28d6261242..fb1d7456f1 100644
--- a/ompi/mca/common/mx/common_mx.h
+++ b/ompi/mca/common/mx/common_mx.h
@@ -28,14 +28,14 @@
  * @retval OMPI_SUCCESS MX successfully initialized
  * @retval OMPI_ERR_NOT_AVAILABLE MX could not be initialized
  */
-int ompi_common_mx_initialize(void);
+OMPI_DECLSPEC int ompi_common_mx_initialize(void);
 
 
 /**
  * Shut down mx library 
  *
  */
-int ompi_common_mx_finalize(void);
+OMPI_DECLSPEC int ompi_common_mx_finalize(void);