diff --git a/simgear/math/SGMathTest.cxx b/simgear/math/SGMathTest.cxx
index f4e5b69f..415a4d59 100644
--- a/simgear/math/SGMathTest.cxx
+++ b/simgear/math/SGMathTest.cxx
@@ -22,8 +22,6 @@
 #include <cstdlib>
 #include <iostream>
 
-#include <plib/sg.h>
-
 #include "SGMath.hxx"
 
 template<typename T>