diff --git a/capinfos.c b/capinfos.c
index e153097219..60c6bc3bdc 100644
--- a/capinfos.c
+++ b/capinfos.c
@@ -49,7 +49,6 @@
 #include <string.h>
 #include <stdarg.h>
 #include <locale.h>
-#include <errno.h>
 
 #include <ws_exit_codes.h>
 #include <wsutil/ws_getopt.h>
diff --git a/capture/iface_monitor.c b/capture/iface_monitor.c
index f742a664a6..bd70b9f4a2 100644
--- a/capture/iface_monitor.c
+++ b/capture/iface_monitor.c
@@ -21,7 +21,6 @@
 
 #include <stdio.h>
 #include <string.h>
-#include <errno.h>
 
 DIAG_OFF_PEDANTIC
 #include <netlink/msg.h>
diff --git a/captype.c b/captype.c
index 20ed504ed6..080a543307 100644
--- a/captype.c
+++ b/captype.c
@@ -19,7 +19,6 @@
 #include <string.h>
 #include <stdarg.h>
 #include <locale.h>
-#include <errno.h>
 
 #include <wsutil/ws_getopt.h>
 
diff --git a/epan/column.c b/epan/column.c
index 12d62b41e5..487c847c0a 100644
--- a/epan/column.c
+++ b/epan/column.c
@@ -13,7 +13,6 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <errno.h>
 
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
diff --git a/epan/dissectors/packet-fcoib.c b/epan/dissectors/packet-fcoib.c
index ae3770de25..ee6f88b392 100644
--- a/epan/dissectors/packet-fcoib.c
+++ b/epan/dissectors/packet-fcoib.c
@@ -15,7 +15,6 @@
 #include "config.h"
 
 #include <stdlib.h>
-#include <errno.h>
 
 #include <epan/packet.h>
 #include <epan/prefs.h>
diff --git a/epan/dissectors/packet-infiniband_sdp.c b/epan/dissectors/packet-infiniband_sdp.c
index ea9c967ec7..7cdb26812c 100644
--- a/epan/dissectors/packet-infiniband_sdp.c
+++ b/epan/dissectors/packet-infiniband_sdp.c
@@ -13,7 +13,6 @@
 #include "config.h"
 
 #include <stdlib.h>
-#include <errno.h>
 
 #include <epan/packet.h>
 #include <epan/prefs.h>
diff --git a/epan/dissectors/packet-iser.c b/epan/dissectors/packet-iser.c
index a40ebd0ce5..33b3f05848 100644
--- a/epan/dissectors/packet-iser.c
+++ b/epan/dissectors/packet-iser.c
@@ -13,7 +13,6 @@
 #include "config.h"
 
 #include <stdlib.h>
-#include <errno.h>
 
 #include <epan/packet.h>
 #include <epan/prefs.h>
diff --git a/epan/dissectors/packet-nvme-rdma.c b/epan/dissectors/packet-nvme-rdma.c
index 2375e33343..548f304fe9 100644
--- a/epan/dissectors/packet-nvme-rdma.c
+++ b/epan/dissectors/packet-nvme-rdma.c
@@ -55,7 +55,6 @@ http://www.iana.org/assignments/service-names-port-numbers/service-names-port-nu
 #include "config.h"
 
 #include <stdlib.h>
-#include <errno.h>
 
 #include <epan/packet.h>
 #include <epan/prefs.h>
diff --git a/epan/dissectors/packet-nvme-tcp.c b/epan/dissectors/packet-nvme-tcp.c
index 1be0763374..4dad7cbfd9 100644
--- a/epan/dissectors/packet-nvme-tcp.c
+++ b/epan/dissectors/packet-nvme-tcp.c
@@ -35,7 +35,6 @@
 
 #include "config.h"
 #include <stdlib.h>
-#include <errno.h>
 #include <epan/packet.h>
 #include <epan/prefs.h>
 #include <epan/conversation.h>
diff --git a/epan/dissectors/packet-rpcrdma.c b/epan/dissectors/packet-rpcrdma.c
index 3f250f0ea1..7b58951c69 100644
--- a/epan/dissectors/packet-rpcrdma.c
+++ b/epan/dissectors/packet-rpcrdma.c
@@ -13,7 +13,6 @@
 #include "config.h"
 
 #include <stdlib.h>
-#include <errno.h>
 
 #include <epan/packet.h>
 #include <epan/prefs.h>
diff --git a/epan/dissectors/packet-snort.c b/epan/dissectors/packet-snort.c
index 06bdea345f..a497064c35 100644
--- a/epan/dissectors/packet-snort.c
+++ b/epan/dissectors/packet-snort.c
@@ -29,8 +29,6 @@
 
 #include "config.h"
 
-#include <errno.h>
-
 #include <epan/packet.h>
 #include <epan/prefs.h>
 #include <epan/expert.h>
diff --git a/epan/ftypes/ftype-ieee-11073-float.c b/epan/ftypes/ftype-ieee-11073-float.c
index 6fa2fdaa12..a1c02442a7 100644
--- a/epan/ftypes/ftype-ieee-11073-float.c
+++ b/epan/ftypes/ftype-ieee-11073-float.c
@@ -16,7 +16,6 @@
 #include <inttypes.h>
 #include <stdio.h>
 #include <math.h>
-#include <errno.h>
 #include <float.h>
 
 #include "strutil.h"
diff --git a/epan/wslua/wslua.h b/epan/wslua/wslua.h
index 682dc53061..f496d539b1 100644
--- a/epan/wslua/wslua.h
+++ b/epan/wslua/wslua.h
@@ -18,7 +18,6 @@
 #define _PACKET_LUA_H
 
 #include <glib.h>
-#include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 #include <math.h>
diff --git a/file.h b/file.h
index a6ed6ce2e9..3a772117ee 100644
--- a/file.h
+++ b/file.h
@@ -12,8 +12,6 @@
 #ifndef __FILE_H__
 #define __FILE_H__
 
-#include <errno.h>
-
 #include <wiretap/wtap.h>
 #include <epan/epan.h>
 #include <epan/print.h>
diff --git a/mergecap.c b/mergecap.c
index beacd3e8a0..41be4e228c 100644
--- a/mergecap.c
+++ b/mergecap.c
@@ -16,7 +16,6 @@
 
 #include <stdio.h>
 #include <stdlib.h>
-#include <errno.h>
 #include <glib.h>
 
 #include <wsutil/ws_getopt.h>
diff --git a/mmdbresolve.c b/mmdbresolve.c
index b14401a7e1..0f0607d913 100644
--- a/mmdbresolve.c
+++ b/mmdbresolve.c
@@ -13,7 +13,6 @@
 
 #include <stdio.h>
 #include <stdlib.h>
-#include <errno.h>
 #include <string.h>
 
 #include <maxminddb.h>
diff --git a/plugins/epan/mate/mate.h b/plugins/epan/mate/mate.h
index 095a098081..79f46af826 100644
--- a/plugins/epan/mate/mate.h
+++ b/plugins/epan/mate/mate.h
@@ -21,7 +21,6 @@
 
 #include <stdio.h>
 #include <string.h>
-#include <errno.h>
 
 #include <wsutil/report_message.h>
 #include <wsutil/wslog.h>
diff --git a/randpkt_core/randpkt_core.c b/randpkt_core/randpkt_core.c
index 85cf0dafd5..9cced12714 100644
--- a/randpkt_core/randpkt_core.c
+++ b/randpkt_core/randpkt_core.c
@@ -15,7 +15,6 @@
 #include "randpkt_core.h"
 
 #include <time.h>
-#include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 #include <wsutil/file_util.h>
diff --git a/sharkd.c b/sharkd.c
index 79a0645659..4aab823d8c 100644
--- a/sharkd.c
+++ b/sharkd.c
@@ -16,7 +16,6 @@
 #include <stdio.h>
 #include <string.h>
 #include <limits.h>
-#include <errno.h>
 #include <signal.h>
 
 #include <glib.h>
diff --git a/ui/decode_as_utils.c b/ui/decode_as_utils.c
index bb2013dad4..3b9bf56e01 100644
--- a/ui/decode_as_utils.c
+++ b/ui/decode_as_utils.c
@@ -11,8 +11,6 @@
 
 #include <stdlib.h>
 
-#include <errno.h>
-
 #include "epan/decode_as.h"
 #include "epan/packet.h"
 #include "epan/prefs.h"
diff --git a/ui/dissect_opts.c b/ui/dissect_opts.c
index 5c179314a0..a716a1a4d6 100644
--- a/ui/dissect_opts.c
+++ b/ui/dissect_opts.c
@@ -15,8 +15,6 @@
 
 #include <string.h>
 
-#include <errno.h>
-
 #include <glib.h>
 
 #include <epan/prefs.h>
diff --git a/ui/qt/filter_dialog.cpp b/ui/qt/filter_dialog.cpp
index 5e0a948efa..1ed86b879d 100644
--- a/ui/qt/filter_dialog.cpp
+++ b/ui/qt/filter_dialog.cpp
@@ -9,8 +9,6 @@
 
 #include <config.h>
 
-#include <errno.h>
-
 #include <glib.h>
 
 #include <wsutil/filter_files.h>
diff --git a/ui/util.c b/ui/util.c
index 935706526a..064d83ca30 100644
--- a/ui/util.c
+++ b/ui/util.c
@@ -14,7 +14,6 @@
 
 #include <stdlib.h>
 #include <string.h>
-#include <errno.h>
 
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
diff --git a/wiretap/5views.c b/wiretap/5views.c
index fc0a9b2b86..c474804a1f 100644
--- a/wiretap/5views.c
+++ b/wiretap/5views.c
@@ -7,7 +7,6 @@
  */
 
 #include "config.h"
-#include <errno.h>
 #include <string.h>
 
 #include "wtap-int.h"
diff --git a/wiretap/aethra.c b/wiretap/aethra.c
index 58e815bb33..3216e74ed9 100644
--- a/wiretap/aethra.c
+++ b/wiretap/aethra.c
@@ -7,7 +7,6 @@
  */
 
 #include "config.h"
-#include <errno.h>
 #include <string.h>
 #include "wtap-int.h"
 #include "file_wrappers.h"
diff --git a/wiretap/ascendtext.c b/wiretap/ascendtext.c
index 5d768cdf3b..71e7273859 100644
--- a/wiretap/ascendtext.c
+++ b/wiretap/ascendtext.c
@@ -12,8 +12,6 @@
 #include "ascend-int.h"
 #include "file_wrappers.h"
 
-#include <errno.h>
-
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
 #endif
diff --git a/wiretap/ber.c b/wiretap/ber.c
index d9182c7532..ead975a412 100644
--- a/wiretap/ber.c
+++ b/wiretap/ber.c
@@ -7,8 +7,6 @@
 
 #include "config.h"
 
-#include <errno.h>
-
 #include "wtap-int.h"
 #include "file_wrappers.h"
 #include <wsutil/buffer.h>
diff --git a/wiretap/btsnoop.c b/wiretap/btsnoop.c
index a8a9393598..3ef146568b 100644
--- a/wiretap/btsnoop.c
+++ b/wiretap/btsnoop.c
@@ -7,7 +7,6 @@
  */
 
 #include "config.h"
-#include <errno.h>
 #include <string.h>
 #include "wtap-int.h"
 #include "file_wrappers.h"
diff --git a/wiretap/capsa.c b/wiretap/capsa.c
index 786137fe28..6083e38ff2 100644
--- a/wiretap/capsa.c
+++ b/wiretap/capsa.c
@@ -7,7 +7,6 @@
  */
 
 #include "config.h"
-#include <errno.h>
 #include <string.h>
 #include "wtap-int.h"
 #include "file_wrappers.h"
diff --git a/wiretap/commview.c b/wiretap/commview.c
index 990a668055..71f9ced287 100644
--- a/wiretap/commview.c
+++ b/wiretap/commview.c
@@ -25,7 +25,6 @@
 #include "config.h"
 
 #include <stdlib.h>
-#include <errno.h>
 #include <string.h>
 
 #include "wtap-int.h"
diff --git a/wiretap/daintree-sna.c b/wiretap/daintree-sna.c
index 6c20cb1ca7..67ae444488 100644
--- a/wiretap/daintree-sna.c
+++ b/wiretap/daintree-sna.c
@@ -34,7 +34,6 @@
 #include "config.h"
 
 #include <stdlib.h>
-#include <errno.h>
 #include <string.h>
 
 #include "wtap-int.h"
diff --git a/wiretap/eyesdn.c b/wiretap/eyesdn.c
index 20669806d8..4d22d6b7af 100644
--- a/wiretap/eyesdn.c
+++ b/wiretap/eyesdn.c
@@ -13,7 +13,6 @@
 
 #include <stdlib.h>
 #include <string.h>
-#include <errno.h>
 
 static int eyesdn_file_type_subtype = -1;
 
diff --git a/wiretap/i4btrace.c b/wiretap/i4btrace.c
index e38e1358a6..1b15972b66 100644
--- a/wiretap/i4btrace.c
+++ b/wiretap/i4btrace.c
@@ -9,7 +9,6 @@
 #include "config.h"
 
 #include <stdlib.h>
-#include <errno.h>
 #include <string.h>
 #include "wtap-int.h"
 #include "file_wrappers.h"
diff --git a/wiretap/ipfix.c b/wiretap/ipfix.c
index b9ed377c4d..2dff3849d4 100644
--- a/wiretap/ipfix.c
+++ b/wiretap/ipfix.c
@@ -52,7 +52,6 @@
 
 #include <stdlib.h>
 #include <string.h>
-#include <errno.h>
 #include "wtap-int.h"
 #include "file_wrappers.h"
 #include "ipfix.h"
diff --git a/wiretap/iptrace.c b/wiretap/iptrace.c
index f9ae4b8d70..2b4e9d63bb 100644
--- a/wiretap/iptrace.c
+++ b/wiretap/iptrace.c
@@ -8,7 +8,6 @@
  */
 #include "config.h"
 #include <stdlib.h>
-#include <errno.h>
 #include <string.h>
 #include "wtap-int.h"
 #include "file_wrappers.h"
diff --git a/wiretap/iseries.c b/wiretap/iseries.c
index f235c5b3e7..180ed01ae5 100644
--- a/wiretap/iseries.c
+++ b/wiretap/iseries.c
@@ -143,7 +143,6 @@ Number  S/R  Length    Timer                        MAC Address   MAC Address
 
 #include <stdlib.h>
 #include <string.h>
-#include <errno.h>
 
 #include <wsutil/str_util.h>
 #include <wsutil/strtoi.h>
diff --git a/wiretap/k12.c b/wiretap/k12.c
index c3b99bba7d..f03e859d0c 100644
--- a/wiretap/k12.c
+++ b/wiretap/k12.c
@@ -14,7 +14,6 @@
 #include "config.h"
 #include <stdlib.h>
 #include <string.h>
-#include <errno.h>
 
 #include "wtap-int.h"
 #include "file_wrappers.h"
diff --git a/wiretap/libpcap.c b/wiretap/libpcap.c
index aa4e2874d8..625a2de067 100644
--- a/wiretap/libpcap.c
+++ b/wiretap/libpcap.c
@@ -10,7 +10,6 @@
 
 #include <stdlib.h>
 #include <string.h>
-#include <errno.h>
 #include "wtap-int.h"
 #include "file_wrappers.h"
 #include "required_file_handlers.h"
diff --git a/wiretap/merge.c b/wiretap/merge.c
index 0c3c919acf..c838c62162 100644
--- a/wiretap/merge.c
+++ b/wiretap/merge.c
@@ -17,7 +17,6 @@
 #define WS_LOG_DOMAIN LOG_DOMAIN_WIRETAP
 
 #include <stdlib.h>
-#include <errno.h>
 
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
diff --git a/wiretap/mime_file.c b/wiretap/mime_file.c
index 25c72e2ce6..a3cce0d14d 100644
--- a/wiretap/mime_file.c
+++ b/wiretap/mime_file.c
@@ -24,7 +24,6 @@
 #include <unistd.h>
 #endif
 
-#include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
diff --git a/wiretap/mp2t.c b/wiretap/mp2t.c
index f9e7bbce4c..a0f3f6112c 100644
--- a/wiretap/mp2t.c
+++ b/wiretap/mp2t.c
@@ -21,7 +21,6 @@
 #include "wtap-int.h"
 #include <wsutil/buffer.h>
 #include "file_wrappers.h"
-#include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
diff --git a/wiretap/mpeg.c b/wiretap/mpeg.c
index b0611c627e..c42199263b 100644
--- a/wiretap/mpeg.c
+++ b/wiretap/mpeg.c
@@ -31,7 +31,6 @@
 #include "wtap-int.h"
 #include <wsutil/buffer.h>
 #include "file_wrappers.h"
-#include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
diff --git a/wiretap/netscaler.c b/wiretap/netscaler.c
index a5963adcc4..c1b229e0fc 100644
--- a/wiretap/netscaler.c
+++ b/wiretap/netscaler.c
@@ -7,7 +7,6 @@
  */
 
 #include "config.h"
-#include <errno.h>
 #include <string.h>
 #include "wtap-int.h"
 #include "file_wrappers.h"
diff --git a/wiretap/nettl.c b/wiretap/nettl.c
index 74723dfb41..2a4627103c 100644
--- a/wiretap/nettl.c
+++ b/wiretap/nettl.c
@@ -12,7 +12,6 @@
 #include "config.h"
 
 #include <stdlib.h>
-#include <errno.h>
 #include <string.h>
 #include "wtap-int.h"
 #include "file_wrappers.h"
diff --git a/wiretap/nettrace_3gpp_32_423.c b/wiretap/nettrace_3gpp_32_423.c
index faac76b913..2b4515239b 100644
--- a/wiretap/nettrace_3gpp_32_423.c
+++ b/wiretap/nettrace_3gpp_32_423.c
@@ -16,7 +16,6 @@
 #include <unistd.h>
 #endif
 
-#include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
diff --git a/wiretap/netxray.c b/wiretap/netxray.c
index 5d8ad2d809..6ba6c7950a 100644
--- a/wiretap/netxray.c
+++ b/wiretap/netxray.c
@@ -8,7 +8,6 @@
 
 #include "config.h"
 
-#include <errno.h>
 #include <string.h>
 #include "wtap-int.h"
 #include "file_wrappers.h"
diff --git a/wiretap/ngsniffer.c b/wiretap/ngsniffer.c
index fb00e9fa66..4ee4eda162 100644
--- a/wiretap/ngsniffer.c
+++ b/wiretap/ngsniffer.c
@@ -42,7 +42,6 @@
  */
 #include "config.h"
 
-#include <errno.h>
 #include <string.h>
 #include "wtap-int.h"
 #include "file_wrappers.h"
diff --git a/wiretap/observer.c b/wiretap/observer.c
index d1a31b42b7..6a745c1437 100644
--- a/wiretap/observer.c
+++ b/wiretap/observer.c
@@ -15,7 +15,6 @@
 #include "config.h"
 
 #include <stdlib.h>
-#include <errno.h>
 #include <string.h>
 #include "wtap-int.h"
 #include "file_wrappers.h"
diff --git a/wiretap/packetlogger.c b/wiretap/packetlogger.c
index 1d9951d320..885d450540 100644
--- a/wiretap/packetlogger.c
+++ b/wiretap/packetlogger.c
@@ -15,7 +15,6 @@
 #include "config.h"
 
 #include <stdlib.h>
-#include <errno.h>
 #include <string.h>
 
 #include "wtap-int.h"
diff --git a/wiretap/pcap-common.c b/wiretap/pcap-common.c
index 2a0e69e7dd..404b43df5c 100644
--- a/wiretap/pcap-common.c
+++ b/wiretap/pcap-common.c
@@ -14,7 +14,6 @@
 
 #include <stdlib.h>
 #include <string.h>
-#include <errno.h>
 #include "wtap-int.h"
 #include "file_wrappers.h"
 #include "atm.h"
diff --git a/wiretap/peekclassic.c b/wiretap/peekclassic.c
index 3fffc80caa..18b926ddba 100644
--- a/wiretap/peekclassic.c
+++ b/wiretap/peekclassic.c
@@ -22,7 +22,6 @@
  */
 
 #include "config.h"
-#include <errno.h>
 #include <string.h>
 
 #include <wsutil/epochs.h>
diff --git a/wiretap/peektagged.c b/wiretap/peektagged.c
index ef9bbbc568..acef34634c 100644
--- a/wiretap/peektagged.c
+++ b/wiretap/peektagged.c
@@ -19,7 +19,6 @@
  */
 
 #include "config.h"
-#include <errno.h>
 #include <string.h>
 #include <stdlib.h>
 #include "wtap-int.h"
diff --git a/wiretap/radcom.c b/wiretap/radcom.c
index 1547a0ec21..6e6c596317 100644
--- a/wiretap/radcom.c
+++ b/wiretap/radcom.c
@@ -8,7 +8,6 @@
 
 #include "config.h"
 
-#include <errno.h>
 #include <string.h>
 #include "wtap-int.h"
 #include "file_wrappers.h"
diff --git a/wiretap/rtpdump.c b/wiretap/rtpdump.c
index 9a2e15e540..705115ff7a 100644
--- a/wiretap/rtpdump.c
+++ b/wiretap/rtpdump.c
@@ -56,7 +56,6 @@
 #include <wsutil/wslog.h>
 #include "rtpdump.h"
 #include <string.h>
-#include <errno.h>
 
 /* NB. I've included the version string in the magic for stronger identification.
  * If we add/change version support, we'll also need to edit:
diff --git a/wiretap/snoop.c b/wiretap/snoop.c
index aa4a4bc3d1..8621be6eaf 100644
--- a/wiretap/snoop.c
+++ b/wiretap/snoop.c
@@ -7,7 +7,6 @@
  */
 
 #include "config.h"
-#include <errno.h>
 #include <string.h>
 #include "wtap-int.h"
 #include "file_wrappers.h"
diff --git a/wiretap/stanag4607.c b/wiretap/stanag4607.c
index 0edbcd1dd4..0b2f2bff43 100644
--- a/wiretap/stanag4607.c
+++ b/wiretap/stanag4607.c
@@ -15,8 +15,6 @@
 
 #include "config.h"
 
-#include <errno.h>
-
 #include "wtap-int.h"
 #include "file_wrappers.h"
 #include <wsutil/buffer.h>
diff --git a/wiretap/tnef.c b/wiretap/tnef.c
index 66db868038..a7b17c3af4 100644
--- a/wiretap/tnef.c
+++ b/wiretap/tnef.c
@@ -7,8 +7,6 @@
 
 #include "config.h"
 
-#include <errno.h>
-
 #include "wtap-int.h"
 #include "file_wrappers.h"
 #include <wsutil/buffer.h>
diff --git a/wiretap/visual.c b/wiretap/visual.c
index 17efa2f809..684a6a2e01 100644
--- a/wiretap/visual.c
+++ b/wiretap/visual.c
@@ -9,7 +9,6 @@
  */
 
 #include "config.h"
-#include <errno.h>
 #include <string.h>
 #include "wtap-int.h"
 #include "file_wrappers.h"
diff --git a/wiretap/vwr.c b/wiretap/vwr.c
index 48272b2691..251ddf524c 100644
--- a/wiretap/vwr.c
+++ b/wiretap/vwr.c
@@ -9,7 +9,6 @@
  */
 #include "config.h"
 
-#include <errno.h>
 #include <string.h>
 
 #include "wtap-int.h"
diff --git a/wiretap/wtap.c b/wiretap/wtap.c
index f2aaff1205..4c9ead0737 100644
--- a/wiretap/wtap.c
+++ b/wiretap/wtap.c
@@ -9,7 +9,6 @@
 #include <config.h>
 
 #include <string.h>
-#include <errno.h>
 
 #include <sys/types.h>
 
diff --git a/wsutil/plugins.c b/wsutil/plugins.c
index 599190cee0..13fce556d4 100644
--- a/wsutil/plugins.c
+++ b/wsutil/plugins.c
@@ -17,7 +17,6 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
-#include <errno.h>
 
 #include <gmodule.h>