diff --git a/unix/configure.ac b/unix/configure.ac
index e55af49..63e158f 100644
--- a/unix/configure.ac
+++ b/unix/configure.ac
@@ -26,7 +26,7 @@
   USE_MITSHM=yes
   ;;
 "IRIX 6"*)
-  X_LIBS="-L/usr/lib32"
+  LDFLAGS="-L/usr/lib32 $LDFLAGS"
   USE_MITSHM=yes
   USE_READDISPLAY=yes
   ;;