diff --git a/configure b/configure
index c5b795f4914..7151b2e988d 100755
--- a/configure
+++ b/configure
@@ -1513,7 +1513,9 @@ case $ac_sys_system/$ac_sys_release in
     ;;
   # On Mac OS X 10.4, defining _POSIX_C_SOURCE or _XOPEN_SOURCE
   # disables platform specific features beyond repair.
-  Darwin/8.*)
+  # On Mac OS X 10.3, defining _POSIX_C_SOURCE or _XOPEN_SOURCE 
+  # has no effect, don't bother defineing them
+  Darwin/[78].*)
     define_xopen_source=no
     ;;
 
diff --git a/configure.in b/configure.in
index 8a73c4fdd33..a8b91d65171 100644
--- a/configure.in
+++ b/configure.in
@@ -173,7 +173,9 @@ case $ac_sys_system/$ac_sys_release in
     ;;
   # On Mac OS X 10.4, defining _POSIX_C_SOURCE or _XOPEN_SOURCE
   # disables platform specific features beyond repair.
-  Darwin/8.*)
+  # On Mac OS X 10.3, defining _POSIX_C_SOURCE or _XOPEN_SOURCE 
+  # has no effect, don't bother defineing them
+  Darwin/[78].*)
     define_xopen_source=no
     ;;