--- ./configure.in.orig	2013-04-16 08:57:38.886870643 +0000
+++ ./configure.in	2013-04-16 09:00:49.735350727 +0000
@@ -275,7 +275,10 @@
        defs="$defs -DHAVE_GSL"
        gsl_libs="-lgslcblas -lgsl"
     fi
-
+    PKG_CHECK_MODULES(GSL, gsl, [
+       defs="$defs -DHAVE_GSL $GSL_CFLAGS"
+       gsl_libs="$GSL_LIBS"
+    ])
 
     dnl the blackhole feature
 
