diff --git a/src/dhcp_device.cpp b/src/dhcp_device.cpp
index 8b1ed4f6c..92de84283 100644
--- a/src/dhcp_device.cpp
+++ b/src/dhcp_device.cpp
@@ -2,13 +2,18 @@
  * @file dhcp_device.cpp
  */
 
+#include <errno.h>
+#include <stdlib.h>
 #include <string.h>
 #include <sys/ioctl.h>
+#include <sys/socket.h>
 #include <unistd.h>
 #include <libexplain/ioctl.h>
 #include <ifaddrs.h>
 #include <pcap.h>
 #include <syslog.h>
+#include <unordered_map>
+#include <unordered_set>
 
 #include "dhcp_device.h"
 
diff --git a/src/dhcp_devman.cpp b/src/dhcp_devman.cpp
index 9fa951e3c..4e849d7a7 100644
--- a/src/dhcp_devman.cpp
+++ b/src/dhcp_devman.cpp
@@ -5,7 +5,7 @@
  */
 
 #include <assert.h>
-#include <errno.h>
+#include <memory>
 #include <string.h>
 #include <syslog.h>
 #include <stdlib.h>
diff --git a/src/dhcp_devman.h b/src/dhcp_devman.h
index 73c1cd6f2..c8a3dad9f 100644
--- a/src/dhcp_devman.h
+++ b/src/dhcp_devman.h
@@ -15,7 +15,6 @@
 #ifndef DHCP_DEVMAN_H_
 #define DHCP_DEVMAN_H_
 
-#include <stdint.h>
 #include <string>
 #include <unordered_map>
 #include <unordered_set>
diff --git a/src/dhcp_mon.cpp b/src/dhcp_mon.cpp
index ef4f6623d..6f53b506d 100644
--- a/src/dhcp_mon.cpp
+++ b/src/dhcp_mon.cpp
@@ -5,15 +5,19 @@
  */
 
 #include <signal.h>
-#include <errno.h>
 #include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
 #include <unistd.h>
 #include <sys/syscall.h>
 #include <assert.h>
 #include <chrono>
 #include <algorithm>
 #include <event2/thread.h>
+#include <memory>
 #include <mutex>
+#include <string>
+#include <unordered_set>
 
 #include "dhcp_mon.h"
 
diff --git a/src/dhcp_mon.h b/src/dhcp_mon.h
index 5a8671b8f..893a56778 100644
--- a/src/dhcp_mon.h
+++ b/src/dhcp_mon.h
@@ -9,6 +9,8 @@
 #ifndef DHCP_MON_H_
 #define DHCP_MON_H_
 
+#include <stddef.h>
+
 /** dhcpmon debug mode control flag, mostly used for logging for more frequent operations */
 extern bool debug_on;
 
diff --git a/src/main.cpp b/src/main.cpp
index e393d0ab5..afcb649b5 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -5,19 +5,16 @@
  *
  */
 
-#include <err.h>
 #include <errno.h>
 #include <libgen.h>
-#include <signal.h>
+#include <stdint.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <semaphore.h>
 #include <syslog.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
-#include <swss/subscriberstatetable.h>
-#include <swss/select.h>
 
 #include "dhcp_mon.h" // starting dhcpmon
 #include "dhcp_devman.h" // for registering interfaces
diff --git a/src/packet_handler.cpp b/src/packet_handler.cpp
index 7ec5d07a3..9ee480cd5 100644
--- a/src/packet_handler.cpp
+++ b/src/packet_handler.cpp
@@ -4,10 +4,13 @@
  *  Implementation of packet handler functions
  */
 
+#include <errno.h>
 #include <net/ethernet.h>
 #include <netinet/ether.h>
 #include <arpa/inet.h>
 #include <linux/if_packet.h>
+#include <string.h>
+#include <vector>
 
 #include "packet_handler.h"
 
diff --git a/src/packet_handler.h b/src/packet_handler.h
index 989a69021..9b17edd49 100644
--- a/src/packet_handler.h
+++ b/src/packet_handler.h
@@ -7,7 +7,7 @@
 #ifndef PACKET_HANDLER_H_
 #define PACKET_HANDLER_H_
 
-#include <string.h>
+#include <string>
 #include <unistd.h>
 #include <net/ethernet.h>
 #include <netinet/ip.h>
diff --git a/src/sock_mgr.cpp b/src/sock_mgr.cpp
index 8d3e48d81..f47c7c85e 100644
--- a/src/sock_mgr.cpp
+++ b/src/sock_mgr.cpp
@@ -2,8 +2,10 @@
  * @file socket_manager.cpp
  */
 
+#include <arpa/inet.h>
 #include <assert.h>
 #include <errno.h>
+#include <memory>
 #include <string.h>
 #include <syslog.h>
 #include <stdlib.h>
diff --git a/src/sock_mgr.h b/src/sock_mgr.h
index 9619a9526..82ead205e 100644
--- a/src/sock_mgr.h
+++ b/src/sock_mgr.h
@@ -9,6 +9,7 @@
 #ifndef SOCKET_MANAGER_H_
 #define SOCKET_MANAGER_H_
 
+#include <stddef.h>
 #include <stdint.h>
 #include <string>
 #include <unordered_map>
diff --git a/src/util.cpp b/src/util.cpp
index aab7d83bd..d492cccb8 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -1,5 +1,8 @@
 #include <arpa/inet.h>
-#include <syslog.h>
+#include <exception>
+#include <memory>
+#include <stdio.h>
+#include <stdlib.h>
 
 #include "util.h"
 #include <swss/subscriberstatetable.h>
diff --git a/src/util.h b/src/util.h
index f4fbd24c3..798b130f1 100644
--- a/src/util.h
+++ b/src/util.h
@@ -2,18 +2,20 @@
 #ifndef UTIL_H
 #define UTIL_H
 
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdint.h>
 #include <string>
-#include <memory>
+#include <string.h>
+#include <utility>
 #include <jsoncpp/json/json.h>
 #include <syslog.h>
 #include <unordered_map>
 #include <vector>
 #include <algorithm>
-#include <functional>
 #include <netinet/ip.h>
 #include <netinet/udp.h>
 #include <netinet/ip6.h>
-#include <event2/event.h>
 
 #define COUNTERS_DB_COUNTER_TABLE_PREFIX "DHCPV4_COUNTER_TABLE:"
 #define COUNTERS_DB_COUNTER_TABLE_V6_PREFIX "DHCPV6_COUNTER_TABLE:"