diff --git a/src/workerd/io/io-context.c++ b/src/workerd/io/io-context.c++
index bc71072f4fa..b4ca3d41dbd 100644
--- a/src/workerd/io/io-context.c++
+++ b/src/workerd/io/io-context.c++
@@ -12,6 +12,7 @@
 
 #include <kj/debug.h>
 
+#include <cmath>
 #include <map>
 
 namespace workerd {