diff --git a/configure b/configure
index 80497aab75..232ba743ef 100755
--- a/configure
+++ b/configure
@@ -140,7 +140,7 @@ LDFLAGS="-g $LDFLAGS"
 
 gcc_flags="-Wold-style-declaration -Wold-style-definition -Wtype-limits"
 gcc_flags="-Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers $gcc_flags"
-gcc_flags="-Wmissing-include-dirs -Wempty-body $gcc_flags"
+gcc_flags="-Wmissing-include-dirs -Wempty-body -Wnested-externs $gcc_flags"
 gcc_flags="-fstack-protector-all $gcc_flags"
 cat > $TMPC << EOF
 int main(void) { return 0; }
diff --git a/feature_to_c.sh b/feature_to_c.sh
index dbf9f19c91..0994d9546e 100644
--- a/feature_to_c.sh
+++ b/feature_to_c.sh
@@ -63,7 +63,6 @@ for input; do
 done
 
 echo >> $output
-echo "extern const char *const xml_builtin[][2];" >> $output
 echo "const char *const xml_builtin[][2] = {" >> $output
 
 for input; do
diff --git a/gdbstub.c b/gdbstub.c
index 2b03ef2aa0..0aa081b13b 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -1504,7 +1504,6 @@ static int memtox(char *buf, const char *mem, int len)
 
 static const char *get_feature_xml(const char *p, const char **newp)
 {
-    extern const char *const xml_builtin[][2];
     size_t len;
     int i;
     const char *name;
diff --git a/gdbstub.h b/gdbstub.h
index 219abdab0e..ce5fdcc223 100644
--- a/gdbstub.h
+++ b/gdbstub.h
@@ -38,4 +38,7 @@ int gdbserver_start(int);
 int gdbserver_start(const char *port);
 #endif
 
+/* in gdbstub-xml.c, generated by feature_to_c.sh */
+extern const char *const xml_builtin[][2];
+
 #endif