diff --git a/qad/utils/qpievaluator.h b/qad/utils/qpievaluator.h
index 50dec7e..056ba88 100644
--- a/qad/utils/qpievaluator.h
+++ b/qad/utils/qpievaluator.h
@@ -23,9 +23,15 @@ const double rad2deg_qpie = 45. / atan(1.);
 inline complexd round_qpie(const complexd & c) {return complexd(round(c.real()), round(c.imag()));}
 inline complexd floor_qpie(const complexd & c) {return complexd(floor(c.real()), floor(c.imag()));}
 inline complexd  ceil_qpie(const complexd & c) {return complexd(ceil(c.real()), ceil(c.imag()));}
-inline complexd atanc_qpie(const complexd & c) {return -complexd(-0.5, 1.) * log((complexd_1 + complexd_i * c) / (complexd_1 - complexd_i * c));}
+#if (__cplusplus >= 201103L) // стандарт C++ 11 или выше
+#  define acosc_qpie acos
+#  define asinc_qpie asin
+#  define atanc_qpie atan
+#else
+inline complexd atanc_qpie(const complexd & c) {return complexd(0., 0.5) * log((complexd_1 - complexd_i * c) / (complexd_1 + complexd_i * c));}
 inline complexd asinc_qpie(const complexd & c) {return -complexd_i * log(complexd_i * c + sqrt(complexd_1 - c * c));}
 inline complexd acosc_qpie(const complexd & c) {return -complexd_i * log(c + complexd_i * sqrt(complexd_1 - c * c));}
+#endif
 
 namespace QPIEvaluatorTypes {
 	static const int operationCount = 14;