diff --git a/qad_utils/qpievaluator.h b/qad_utils/qpievaluator.h
index fad0afc..9bf96a7 100644
--- a/qad_utils/qpievaluator.h
+++ b/qad_utils/qpievaluator.h
@@ -27,6 +27,7 @@
 #include <complex>
 
 #ifndef PIP_MATH_COMPLEX
+#define QPIEVALUATOR_COMPLEX
 typedef std::complex<double> complexd;
 const complexd complexd_i(0., 1.);
 const complexd complexd_0(0.);