diff --git a/src/solvers/smt2/smt2_conv.h b/src/solvers/smt2/smt2_conv.h
index a0c0382e395..fa6d79aec05 100644
--- a/src/solvers/smt2/smt2_conv.h
+++ b/src/solvers/smt2/smt2_conv.h
@@ -14,6 +14,7 @@ Author: Daniel Kroening, kroening@kroening.com
 #include <util/std_expr.h>
 #include <util/threeval.h>
 
+#include <cstdint>
 #include <map>
 #include <set>
 #include <sstream>
diff --git a/src/util/dense_integer_map.h b/src/util/dense_integer_map.h
index 8160d80d079..60a12b8f988 100644
--- a/src/util/dense_integer_map.h
+++ b/src/util/dense_integer_map.h
@@ -12,12 +12,13 @@ Author: Diffblue Ltd
 #ifndef CPROVER_UTIL_DENSE_INTEGER_MAP_H
 #define CPROVER_UTIL_DENSE_INTEGER_MAP_H
 
+#include <util/invariant.h>
+
+#include <cstdint>
 #include <limits>
 #include <unordered_set>
 #include <vector>
 
-#include <util/invariant.h>
-
 /// Identity functor. When we use C++20 this can be replaced with std::identity.
 class identity_functort
 {