--- crrcsim-0.9.11/configure.ac
+++ crrcsim-0.9.11/configure.ac
@@ -229,7 +229,7 @@
       has_CGAL="yes  (found CGAL v3)"
     fi   
     CGAL_CFLAGS=-frounding-math
-    CGAL_LIBS=-lCGAL
+    CGAL_LIBS="-lCGAL -lgmp"
     AC_DEFINE([WINDDATA3D], [1], [Import code for wind data, needs CGAL, 0 to disable])
 else
     has_CGAL="no   (CGAL not found)"