diff --git a/configure.in b/configure.in
index 4ea07df337..e7b91e2cf6 100644
--- a/configure.in
+++ b/configure.in
@@ -247,6 +247,7 @@ dnl CPU_TYPE=ppc64
     PLATFORM=HPUX
     AC_DEFINE(HPUX, 1, [Define this if OS is HP-UX])
     EDITLINE_FLG=Y
+    SHRLIB_EXT=so
     libdir=/usr/lib/pa20_64
     ;;