diff --git a/src/ccutil/clst.h b/src/ccutil/clst.h
index 54f1919cc1..e384097d88 100644
--- a/src/ccutil/clst.h
+++ b/src/ccutil/clst.h
@@ -22,6 +22,7 @@
 #include "lsterr.h"
 #include "serialis.h"
 
+#include <algorithm>
 #include <cstdio>
 
 namespace tesseract {
diff --git a/src/ccutil/elst.h b/src/ccutil/elst.h
index f87e59eed6..f732846af7 100644
--- a/src/ccutil/elst.h
+++ b/src/ccutil/elst.h
@@ -22,6 +22,7 @@
 #include "lsterr.h"
 #include "serialis.h"
 
+#include <algorithm>
 #include <cstdio>
 
 namespace tesseract {
diff --git a/src/ccutil/elst2.h b/src/ccutil/elst2.h
index ad7167a402..007818f57e 100644
--- a/src/ccutil/elst2.h
+++ b/src/ccutil/elst2.h
@@ -22,6 +22,7 @@
 #include "lsterr.h"
 #include "serialis.h"
 
+#include <algorithm>
 #include <cstdio>
 
 namespace tesseract {