diff --git a/opm/io/eclipse/EclFile.hpp b/opm/io/eclipse/EclFile.hpp
index 38af36a3e..6ead84964 100644
--- a/opm/io/eclipse/EclFile.hpp
+++ b/opm/io/eclipse/EclFile.hpp
@@ -28,6 +28,7 @@
 #include <tuple>
 #include <unordered_map>
 #include <vector>
+#include <cstdint>
 
 namespace Opm { namespace EclIO {
 
diff --git a/opm/io/eclipse/EclUtil.hpp b/opm/io/eclipse/EclUtil.hpp
index a0c99b7d9..4945e6d98 100644
--- a/opm/io/eclipse/EclUtil.hpp
+++ b/opm/io/eclipse/EclUtil.hpp
@@ -25,6 +25,7 @@
 #include <tuple>
 #include <vector>
 #include <functional>
+#include <cstdint>
 
 namespace Opm { namespace EclIO {