diff --git a/dpi/file.cc b/dpi/file.cc
index 57d62ee..b8bf6ef 100644
--- a/dpi/file.cc
+++ b/dpi/file.cc
@@ -42,6 +42,7 @@
 #include <string>
 #include <vector>
 #include <compare>
+#include <algorithm>
 
 /*
  * Debugging macros
diff --git a/dw/findtext.cc b/dw/findtext.cc
index 601fc35..765369a 100644
--- a/dw/findtext.cc
+++ b/dw/findtext.cc
@@ -24,6 +24,8 @@
 #include "../lout/debug.hh"
 #include "../lout/msg.h"
 
+#include <algorithm>
+
 namespace dw {
 namespace core {
 
diff --git a/src/bw.cc b/src/bw.cc
index 2c831ed..1cc9642 100644
--- a/src/bw.cc
+++ b/src/bw.cc
@@ -22,6 +22,7 @@
 #include "uicmd.hh"
 
 #include <cassert>
+#include <algorithm>
 
 /*
  * Local Data
diff --git a/src/css.hh b/src/css.hh
index 0f7de69..77cd854 100644
--- a/src/css.hh
+++ b/src/css.hh
@@ -17,6 +17,7 @@
 #include <memory>
 #include <vector>
 #include <array>
+#include <algorithm>
 #include <map>
 
 #include "dw/core.hh"
diff --git a/src/hsts.cc b/src/hsts.cc
index 75e2357..0dbe98b 100644
--- a/src/hsts.cc
+++ b/src/hsts.cc
@@ -37,6 +37,7 @@
 #include <string>
 #include <memory>
 #include <vector>
+#include <algorithm>
 
 struct HstsData_t {
    std::string host;
diff --git a/src/keys.cc b/src/keys.cc
index 9e1c925..6cda51a 100644
--- a/src/keys.cc
+++ b/src/keys.cc
@@ -24,6 +24,7 @@
 #include <vector>
 #include <string>
 #include <memory>
+#include <algorithm>
 
 /*
  *  Local data types