diff --git a/c/src/exec/libcsupport/src/unixlibc.c b/c/src/exec/libcsupport/src/unixlibc.c
index 2f1e725b6a..3e757e313d 100644
--- a/c/src/exec/libcsupport/src/unixlibc.c
+++ b/c/src/exec/libcsupport/src/unixlibc.c
@@ -2,6 +2,8 @@
  *  $Id$
  */
 
+#include <rtems.h>
+
 #if defined(RTEMS_UNIXLIB)
 
 void libc_init(int reentrant)
diff --git a/c/src/lib/libc/unixlibc.c b/c/src/lib/libc/unixlibc.c
index 2f1e725b6a..3e757e313d 100644
--- a/c/src/lib/libc/unixlibc.c
+++ b/c/src/lib/libc/unixlibc.c
@@ -2,6 +2,8 @@
  *  $Id$
  */
 
+#include <rtems.h>
+
 #if defined(RTEMS_UNIXLIB)
 
 void libc_init(int reentrant)
diff --git a/cpukit/libcsupport/src/unixlibc.c b/cpukit/libcsupport/src/unixlibc.c
index 2f1e725b6a..3e757e313d 100644
--- a/cpukit/libcsupport/src/unixlibc.c
+++ b/cpukit/libcsupport/src/unixlibc.c
@@ -2,6 +2,8 @@
  *  $Id$
  */
 
+#include <rtems.h>
+
 #if defined(RTEMS_UNIXLIB)
 
 void libc_init(int reentrant)