diff --git a/tools/vtk2h5grid/Makefile.am b/tools/vtk2h5grid/Makefile.am
index 739551a..d3d186c 100644
--- a/tools/vtk2h5grid/Makefile.am
+++ b/tools/vtk2h5grid/Makefile.am
@@ -4,7 +4,7 @@ LDFLAGS += -L${abs_top_builddir}/src/lib
 
 LDADD = 
 
-LDADD += -lH5hut -lvtkIO -lvtkFiltering -lvtkCommon -lvtksys
+LDADD += -lH5hut -lvtkIO -lvtkFiltering -lvtkCommon -lvtksys -lpthread -ldl
 
 
 bin_PROGRAMS =