--- src/bin/benchmark.cc
+++ src/bin/benchmark.cc
@@ -28,10 +28,12 @@
 #include <ktoblzcheck.h>
 #include <iostream>
 #include <fstream>
-#include <stdio.h>
+#include <cstdio>
+#include <cstdlib>
+#include <climits>
+#include <cassert>
 #include <cstdlib>
 #include <climits>
-#include <assert.h>
 
 using namespace std;
 
--- src/bin/ktoblzcheck.cc
+++ src/bin/ktoblzcheck.cc
@@ -33,7 +33,7 @@
 #endif
 
 #include <cstdlib>
-#include <stdio.h>
+#include <cstdio>
 #include <ktoblzcheck.h>
 #include <iostream>
 #include <fstream>
--- src/lib/accnum.cc
+++ src/lib/accnum.cc
@@ -36,7 +36,7 @@
 # include "config.h"
 #endif
 #include "ktoblzcheck.h"
-#include <assert.h>
+#include <cassert>
 #include <string.h> // for strdup()
 
 
--- src/lib/algorithms.cc
+++ src/lib/algorithms.cc
@@ -31,7 +31,8 @@
 #include "binreloc.h"
 #include <fstream>
 #include <iostream>
-#include <assert.h>
+#include <cassert>
+#include <cstdlib>
 
 
 #if OS_WIN32
--- src/lib/iban.cc
+++ src/lib/iban.cc
@@ -33,7 +33,7 @@
 
 #include "algorithms.h"
 #include "iban.h"
-#include <assert.h>
+#include <cassert>
 
 // ////////////////////////////////////////////////////////////
 
--- src/lib/ktoblzcheck.cc
+++ src/lib/ktoblzcheck.cc
@@ -35,6 +35,7 @@
 #include <cassert>
 #include <cstdio>
 #include <cstdlib>
+#include <cstring>
 
 // The actual algorithms for number checking are there
 #include "algorithms.h"