diff --git a/connection.cpp b/connection.cpp
index cfc03d2..63aac45 100644
--- a/connection.cpp
+++ b/connection.cpp
@@ -21,7 +21,7 @@
 
 
 #include <iostream>
-#include <assert.h>
+#include <cassert>
 #include <malloc.h>
 #include "nethogs.h"
 #include "connection.h"
diff --git a/conninode.cpp b/conninode.cpp
index 8eeb76d..a524fd6 100644
--- a/conninode.cpp
+++ b/conninode.cpp
@@ -22,7 +22,7 @@
 
 #include <netinet/in.h>
 #include <map>
-#include <stdio.h>
+#include <cstdio>
 #include <stdlib.h>
 
 #include "nethogs.h"
diff --git a/cui.cpp b/cui.cpp
index f31ea20..fe2f432 100644
--- a/cui.cpp
+++ b/cui.cpp
@@ -24,8 +24,8 @@
 #include <string>
 #include <pwd.h>
 #include <sys/types.h>
-#include <stdlib.h>
-#include <errno.h>
+#include <cstdlib>
+#include <cerrno>
 #include <cstdlib>
 #include <algorithm>
 
diff --git a/decpcap.c b/decpcap.c
index b573caa..0057fef 100644
--- a/decpcap.c
+++ b/decpcap.c
@@ -25,7 +25,7 @@
 #include <netinet/ip.h>
 #include <netinet/ip6.h>
 #include <netinet/tcp.h>
-#include <string.h> // for memcpy
+#include <cstring> // for memcpy
 #include <pcap.h>
 #include "decpcap.h"
 
diff --git a/inode2prog.cpp b/inode2prog.cpp
index f4e6d1c..8ce5020 100644
--- a/inode2prog.cpp
+++ b/inode2prog.cpp
@@ -21,20 +21,19 @@
 
 
 #include <sys/types.h>
-#include <errno.h>
-#include <string.h>
+#include <cerrno>
+#include <cstring>
 #include <dirent.h>
 #include <ctype.h>
 #include <cstdlib>
 #include <iostream>
-#include <stdio.h>
-#include <stdlib.h>
+#include <cstdio>
 #include <unistd.h>
 #include <string>
 #include <map>
 #include <sys/stat.h>
 #include <fcntl.h>
-#include <limits.h>
+#include <climits>
 
 #include "inode2prog.h"
 
diff --git a/nethogs.cpp b/nethogs.cpp
index 1d4558b..6bf71dd 100644
--- a/nethogs.cpp
+++ b/nethogs.cpp
@@ -22,15 +22,15 @@
 #include "nethogs.h"
 
 #include <iostream>
-#include <stdio.h>
-#include <stdlib.h>
-#include <assert.h>
+#include <cstdio>
+#include <cstdlib>
+#include <cassert>
 #include <unistd.h>
-#include <signal.h>
+#include <csignal>
 #include <string>
-#include <string.h>
+#include <cstring>
 #include <getopt.h>
-#include <stdarg.h>
+#include <cstdarg>
 
 #include <netinet/ip.h>
 #include <netinet/ip6.h>
diff --git a/nethogs.h b/nethogs.h
index 5b33cbf..0418ca5 100644
--- a/nethogs.h
+++ b/nethogs.h
@@ -27,8 +27,8 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <arpa/inet.h>
-#include <assert.h>
-#include <string.h>
+#include <cassert>
+#include <cstring>
 #include <malloc.h>
 #include <iostream>
 
diff --git a/packet.cpp b/packet.cpp
index fa36838..82073dc 100644
--- a/packet.cpp
+++ b/packet.cpp
@@ -26,13 +26,13 @@
 #include <netinet/tcp.h>
 #include <netinet/in.h>
 #include <malloc.h>
-#include <assert.h>
+#include <cassert>
 #include <net/if.h>
 #include <net/ethernet.h>
 #include <netinet/ip.h>
 #include <netinet/ip6.h>
 #include <sys/ioctl.h>
-#include <stdio.h>
+#include <cstdio>
 // #include "inet6.c"
 
 local_addr * local_addrs = NULL;
diff --git a/process.h b/process.h
index d326d29..728649b 100644
--- a/process.h
+++ b/process.h
@@ -23,7 +23,7 @@
 #ifndef __PROCESS_H
 #define __PROCESS_H
 
-#include <assert.h>
+#include <cassert>
 #include "nethogs.h"
 #include "connection.h"
 
diff --git a/refresh.cpp b/refresh.cpp
index 3ea4e0d..19341d0 100644
--- a/refresh.cpp
+++ b/refresh.cpp
@@ -21,7 +21,7 @@
 
 
 #include <iostream>
-#include <signal.h>
+#include <csignal>
 #include <unistd.h>
 #include "nethogs.h"