diff --git a/ChangeLog b/ChangeLog
index e3907beef71..9e3d3889c65 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2009-05-07  Dave Korn  <dave.korn.cygwin@gmail.com>
+
+	* configure.ac ($with_ppl):  Default to no if not supplied.
+	($with_cloog):  Likewise.
+	configure:  Regenerate.
+
 2009-04-27  James E. Wilson  <wilson@codesourcery.com>
 
 	* MAINTAINERS: Update my e-mail address.
diff --git a/configure b/configure
index 45d85c98bd9..dd525c807ba 100755
--- a/configure
+++ b/configure
@@ -4843,6 +4843,8 @@ pplinc=
 if test "${with_ppl+set}" = set; then
   withval="$with_ppl"
 
+else
+  with_ppl=no
 fi;
 
 # Check whether --with-ppl_include or --without-ppl_include was given.
@@ -4961,6 +4963,8 @@ clooginc=" -DCLOOG_PPL_BACKEND "
 if test "${with_cloog+set}" = set; then
   withval="$with_cloog"
 
+else
+  with_cloog=no
 fi;
 
 # Check whether --with-cloog_include or --without-cloog_include was given.
diff --git a/configure.ac b/configure.ac
index 0bb26e83a4a..a1e11c65071 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1339,7 +1339,7 @@ pplinc=
 
 AC_ARG_WITH(ppl, [  --with-ppl=PATH         Specify prefix directory for the installed PPL package
                           Equivalent to --with-ppl-include=PATH/include
-                          plus --with-ppl-lib=PATH/lib])
+                          plus --with-ppl-lib=PATH/lib],, with_ppl=no)
 AC_ARG_WITH(ppl_include, [  --with-ppl-include=PATH Specify directory for installed PPL include files])
 AC_ARG_WITH(ppl_lib, [  --with-ppl-lib=PATH     Specify the directory for the installed PPL library])
 
@@ -1394,7 +1394,7 @@ clooginc=" -DCLOOG_PPL_BACKEND "
 
 AC_ARG_WITH(cloog, [  --with-cloog=PATH       Specify prefix directory for the installed CLooG-PPL package
                           Equivalent to --with-cloog-include=PATH/include
-                          plus --with-cloog-lib=PATH/lib])
+                          plus --with-cloog-lib=PATH/lib],, with_cloog=no)
 AC_ARG_WITH(cloog_include, [  --with-cloog-include=PATH Specify directory for installed CLooG include files])
 AC_ARG_WITH(cloog_lib, [  --with-cloog-lib=PATH   Specify the directory for the installed CLooG library])