diff --git a/src/libCom/osi/os/RTEMS/osiUnistd.h b/src/libCom/osi/os/RTEMS/osiUnistd.h
index d3b73509a..84e7ba2f3 100644
--- a/src/libCom/osi/os/RTEMS/osiUnistd.h
+++ b/src/libCom/osi/os/RTEMS/osiUnistd.h
@@ -24,6 +24,7 @@
  */
 
 #include <unistd.h>
+#include <ieeefp.h>
 
 /*
  * Some systems fail to provide prototypes of these functions.