diff --git a/configure b/configure
index ad591c87f9001c6f3383547a073cd4995d0249ea..af9ab40a4a04db600fdeb6f7591617b9a91e21d5 100755
--- a/configure
+++ b/configure
@@ -1935,7 +1935,7 @@ case $system in
         fi
         rm -f conftest*
 	;;
-    IRIX-6* | IRIX64-6* | IRIX-64-6*)
+    IRIX-5* | IRIX-6* | IRIX64-6* | IRIX-64-6*)
         echo $ac_n "checking whether ${CC} accepts -LANG:std""... $ac_c" 1>&6
         echo 'void f(){}' > conftest.c
         if test -z "`${CC} -LANG:std -c conftest.c 2>&1`"; then
diff --git a/configure.in b/configure.in
index 351de58db25072a5c2b9d7218973d7b9c9762e7d..5310fb9c9ba689101899911bf6d263c69d42974a 100644
--- a/configure.in
+++ b/configure.in
@@ -31,7 +31,7 @@ case $system in
         fi
         rm -f conftest*
 	;;  
-    IRIX-6* | IRIX64-6* | IRIX-64-6*)
+    IRIX-5* | IRIX-6* | IRIX64-6* | IRIX-64-6*)
         echo $ac_n "checking whether ${CC} accepts -LANG:std""... $ac_c" 1>&6
         echo 'void f(){}' > conftest.c
         if test -z "`${CC} -LANG:std -c conftest.c 2>&1`"; then