diff --git a/src/db/db/dbPolygon.h b/src/db/db/dbPolygon.h
index 1b59dfc5f..3d7657ba2 100644
--- a/src/db/db/dbPolygon.h
+++ b/src/db/db/dbPolygon.h
@@ -41,6 +41,7 @@
 #include "tlAssert.h"
 
 #include <cstddef>
+#include <cmath>
 #include <string>
 #include <vector>
 #include <iterator>