diff -Naur lensfun-0.3.4.orig/apps/lenstool/image.cpp lensfun-0.3.4/apps/lenstool/image.cpp
--- lensfun-0.3.4.orig/apps/lenstool/image.cpp	2023-07-12 20:24:04.000000000 +0200
+++ lensfun-0.3.4/apps/lenstool/image.cpp	2023-07-13 14:14:46.308018100 +0200
@@ -24,6 +24,7 @@
 #define unlink _unlink
 #else
 #include <unistd.h>
+#define _USE_MATH_DEFINES
 #include <math.h>
 #endif
 
