diff --git a/Source/cmDiagnostics.h b/Source/cmDiagnostics.h
index 84fe098b48..6c9e7b49aa 100644
--- a/Source/cmDiagnostics.h
+++ b/Source/cmDiagnostics.h
@@ -101,7 +101,11 @@ public:
     cm::string_view name);
 
   /** Represent a set of diagnostic category actions.  */
-  using DiagnosticMap = std::array<DiagnosticAction, CategoryCount>;
+  struct DiagnosticMap : public std::array<DiagnosticAction, CategoryCount>
+  {
+    DiagnosticMap()
+      : array{} {};
+  };
 };
 
 using cmDiagnosticCategory = cmDiagnostics::DiagnosticCategory;
diff --git a/Source/cmMakefile.cxx b/Source/cmMakefile.cxx
index 11b54463e6..e2b454959b 100644
--- a/Source/cmMakefile.cxx
+++ b/Source/cmMakefile.cxx
@@ -5,6 +5,7 @@
 #include "cmMakefile.h"
 
 #include <algorithm>
+#include <array>
 #include <cassert>
 #include <cstdio>
 #include <cstdlib>
diff --git a/Source/cmMessenger.cxx b/Source/cmMessenger.cxx
index 1d5d41d7c2..cbfe69f3f8 100644
--- a/Source/cmMessenger.cxx
+++ b/Source/cmMessenger.cxx
@@ -3,6 +3,7 @@
 #include "cmMessenger.h"
 
 #include <algorithm>
+#include <array>
 #include <sstream>
 #include <utility>