diff --git a/autoconf/configure.ac b/autoconf/configure.ac
index 3bd7496585d..8c6d697fd8b 100644
--- a/autoconf/configure.ac
+++ b/autoconf/configure.ac
@@ -111,6 +111,9 @@ AC_CACHE_CHECK([type of operating system we're on],
   *-*-freebsd*) 
     llvm_cv_os_type="FreeBSD" 
     llvm_cv_platform_type="Unix" ;;
+  *-*-hpux*) 
+    llvm_cv_os_type="HP-UX" 
+    llvm_cv_platform_type="Unix" ;;
   *-*-interix*) 
     llvm_cv_os_type="Interix"
     llvm_cv_platform_type="Unix" ;;