diff --git a/src/s/hpux10-20.h b/src/s/hpux10-20.h
new file mode 100644
index 00000000000..8e661188d72
--- /dev/null
+++ b/src/s/hpux10-20.h
@@ -0,0 +1,11 @@
+#include "hpux10.h"
+
+#define HPUX10_20
+
+/* otherwise sigunblock wont be defined */
+#define POSIX_SIGNALS
+
+/* Polling problems (interrupted system call) reported for HP-UX 10.10
+   don't exist from 10.20 on (see process.c) */
+#undef POLL_INTERRUPTED_SYS_CALL
+