diff --git a/src/common/bspf.hxx b/src/common/bspf.hxx
index 7ecd32d78..f3a155a7a 100644
--- a/src/common/bspf.hxx
+++ b/src/common/bspf.hxx
@@ -55,6 +55,7 @@ using uInt64 = uint64_t;
 #include <cctype>
 #include <cstdio>
 #include <ctime>
+#include <numbers>
 #include <utility>
 #include <vector>