diff --git a/Tests/FileIO/TestTetGenInterface.cpp b/Tests/FileIO/TestTetGenInterface.cpp
index ef995e9a70dc55ff90ed88e72ea9661f1e89237a..ca06839b0714a6cc6e24f208153962cfb21253b8 100644
--- a/Tests/FileIO/TestTetGenInterface.cpp
+++ b/Tests/FileIO/TestTetGenInterface.cpp
@@ -20,6 +20,7 @@
 
 #include "filesystem.h"
 #include "Applications/FileIO/TetGenInterface.h"
+#include "BaseLib/StringTools.h"
 #include "InfoLib/TestInfo.h"
 #include "MeshLib/IO/readMeshFromFile.h"
 #include "GeoLib/GEOObjects.h"