diff --git a/src/qforte/qubit_basis.h b/src/qforte/qubit_basis.h
index cd319f9b..28827729 100644
--- a/src/qforte/qubit_basis.h
+++ b/src/qforte/qubit_basis.h
@@ -1,3 +1,4 @@
+#include <cstdint>
 #include <numeric>
 #include <string>
 
diff --git a/src/qforte/sq_op_pool.h b/src/qforte/sq_op_pool.h
index 22707e62..4b837807 100644
--- a/src/qforte/sq_op_pool.h
+++ b/src/qforte/sq_op_pool.h
@@ -1,6 +1,7 @@
 #ifndef _sq_op_pool_h_
 #define _sq_op_pool_h_
 
+#include <cstdint>
 #include <complex>
 #include <string>
 #include <vector>