diff --git a/tests/lbpm_morphdrain_pp.cpp b/tests/lbpm_morphdrain_pp.cpp
index c437b82d..905172d7 100644
--- a/tests/lbpm_morphdrain_pp.cpp
+++ b/tests/lbpm_morphdrain_pp.cpp
@@ -11,7 +11,7 @@
 #include <sstream>
 #include "common/Array.h"
 #include "common/Domain.h"
-
+#include "analysis/distance.h"
 
 //*************************************************************************
 // Morpohological drainage pre-processor