diff --git a/configure b/configure
index 6955d9d0..217fdd46 100755
--- a/configure
+++ b/configure
@@ -2522,7 +2522,7 @@ if test "$IPV6" != "no"; then
 fi
 
 if test "x$GXX" = "xyes"; then
-	appendCXX -Wall -W -Wno-unused -Woverloaded-virtual
+	appendCXX -Wall -W -Wno-unused -Woverloaded-virtual -Wshadow
 fi
 
 ac_ext=c
diff --git a/configure.in b/configure.in
index 4f375a00..2f3253bf 100644
--- a/configure.in
+++ b/configure.in
@@ -98,7 +98,7 @@ if test "$IPV6" != "no"; then
 fi
 
 if test "x$GXX" = "xyes"; then
-	appendCXX -Wall -W -Wno-unused -Woverloaded-virtual
+	appendCXX -Wall -W -Wno-unused -Woverloaded-virtual -Wshadow
 fi
 
 AC_CHECK_LIB( gnugetopt, getopt_long,)