diff --git a/readline/sysdep-irix.h b/readline/sysdep-irix.h
new file mode 100644
index 00000000000..e69de15a80e
--- /dev/null
+++ b/readline/sysdep-irix.h
@@ -0,0 +1,12 @@
+/* System-dependent stuff, for SGI irix */
+
+#ifdef __GNUC__
+#define alloca __builtin_alloca
+#else
+extern char *alloca ();
+#endif
+
+#include <sys/types.h>
+#include <sys/stream.h>
+#include <sys/dir.h>
+typedef struct direct dirent;
diff --git a/readline/sysdep-newsos.h b/readline/sysdep-newsos.h
new file mode 100755
index 00000000000..96078a23c10
--- /dev/null
+++ b/readline/sysdep-newsos.h
@@ -0,0 +1,10 @@
+/* System-dependent stuff, for ``normal'' systems */
+
+#ifdef __GNUC__
+#define alloca __builtin_alloca
+#else
+extern char *alloca ();
+#endif
+
+#include <sys/dir.h>
+typedef struct direct dirent;
diff --git a/readline/sysdep-oldbsd.h b/readline/sysdep-oldbsd.h
new file mode 100755
index 00000000000..96078a23c10
--- /dev/null
+++ b/readline/sysdep-oldbsd.h
@@ -0,0 +1,10 @@
+/* System-dependent stuff, for ``normal'' systems */
+
+#ifdef __GNUC__
+#define alloca __builtin_alloca
+#else
+extern char *alloca ();
+#endif
+
+#include <sys/dir.h>
+typedef struct direct dirent;
diff --git a/readline/sysdep-sco.h b/readline/sysdep-sco.h
new file mode 100644
index 00000000000..31af763b447
--- /dev/null
+++ b/readline/sysdep-sco.h
@@ -0,0 +1,13 @@
+/* System-dependent stuff, for SCO systems */
+
+#include <malloc.h>
+
+#ifdef __GNUC__
+#define alloca __builtin_alloca
+#endif
+
+#include <sys/types.h>
+#include <sys/stream.h>
+#include <sys/ptem.h>
+#include <dirent.h>
+typedef struct dirent dirent;