#
# Define GNU_SOURCE so perl will be properly detected
#
--- a/configure.ac
+++ b/configure.ac
@@ -48,6 +48,8 @@
 
 PKG_PROG_PKG_CONFIG
 
+AC_GNU_SOURCE
+
 AC_CACHE_CHECK([if Bison is the parser generator],
   [collectd_cv_prog_bison],
   [
