diff --git a/include/libint2/dfbs_generator.h b/include/libint2/dfbs_generator.h
index a639c6dd2..750f54b69 100644
--- a/include/libint2/dfbs_generator.h
+++ b/include/libint2/dfbs_generator.h
@@ -26,11 +26,11 @@
 #include <libint2/basis.h>
 #include <libint2/boys.h>
 #include <libint2/pivoted_cholesky.h>
-#include <math.h>
 
 #include <Eigen/Dense>
 #include <Eigen/Eigenvalues>
 #include <algorithm>
+#include <cmath>
 
 namespace libint2 {
 
diff --git a/include/libint2/util/intrinsic_types.h b/include/libint2/util/intrinsic_types.h
index fc874d394..7c62bf66e 100644
--- a/include/libint2/util/intrinsic_types.h
+++ b/include/libint2/util/intrinsic_types.h
@@ -22,12 +22,13 @@
 #define _libint2_include_libint2intrinsictypes_h_
 
 #include <libint2/config.h>
-#include <limits.h>
+
+#include <climits>
 
 /* determine default LIBINT2 64-bit integer */
 #ifdef HAVE_STDINT_H
 
-#include <stdint.h>
+#include <cstdint>
 /* because mpz_class does not mesh with long long types, only use those when
  * absolutely necessary */
 #if UINT_LEAST64_MAX != ULONG_MAX