diff --git a/src/V3Width.cpp b/src/V3Width.cpp
index 9a2a106ea..d17e1c4c6 100644
--- a/src/V3Width.cpp
+++ b/src/V3Width.cpp
@@ -77,6 +77,7 @@
 #include "V3String.h"
 #include "V3Task.h"
 
+#include <algorithm>
 #include <cstdarg>
 
 // More code; this file was getting too large; see actions there