diff --git a/pcb_calculator/transline/transline.cpp b/pcb_calculator/transline/transline.cpp
index 805e4bf168..165a6fcbd0 100644
--- a/pcb_calculator/transline/transline.cpp
+++ b/pcb_calculator/transline/transline.cpp
@@ -61,6 +61,8 @@ inline double atanh(double x)
 
   return log((1.0+x)/(1.0-x))/2.0;
 }
+#else
+using namespace std;
 #endif