diff --git a/src/DNS_Mgr.cc b/src/DNS_Mgr.cc
index 46739eeddf..8440d15de5 100644
--- a/src/DNS_Mgr.cc
+++ b/src/DNS_Mgr.cc
@@ -1,5 +1,7 @@
 // See the file "COPYING" in the main distribution directory for copyright.
 
+#include <unistd.h>
+
 #include "zeek/DNS_Mgr.h"
 
 #include "zeek/zeek-config.h"
@@ -10,7 +12,6 @@
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/types.h>
-#include <unistd.h>
 #include <algorithm>
 #include <cerrno>
 #include <cstdlib>
diff --git a/src/Options.cc b/src/Options.cc
index 31e5b38c86..458a52f93b 100644
--- a/src/Options.cc
+++ b/src/Options.cc
@@ -1,11 +1,11 @@
 // See the file "COPYING" in the main distribution directory for copyright.
 
+#include <unistd.h>
+
 #include "zeek/Options.h"
 
 #include "zeek/zeek-config.h"
 
-#include <unistd.h>
-
 #include "zeek/ScriptProfile.h"
 #include "zeek/script_opt/ScriptOpt.h"
 
diff --git a/src/iosource/BPF_Program.cc b/src/iosource/BPF_Program.cc
index 71c9f7ee27..1ee1952143 100644
--- a/src/iosource/BPF_Program.cc
+++ b/src/iosource/BPF_Program.cc
@@ -1,5 +1,8 @@
 // See the file "COPYING" in the main distribution directory for copyright.
 
+#include <unistd.h>
+#include <sys/socket.h>
+
 #include "zeek/iosource/BPF_Program.h"
 
 #include "zeek/zeek-config.h"
diff --git a/src/main.cc b/src/main.cc
index 7436292039..aeb15627f5 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -1,5 +1,7 @@
 // See the file "COPYING" in the main distribution directory for copyright.
 
+#include <unistd.h>
+
 #include "zeek/zeek-config.h"
 
 #include "zeek/RunState.h"
diff --git a/src/zeek-setup.cc b/src/zeek-setup.cc
index c39b9a8833..b718988b82 100644
--- a/src/zeek-setup.cc
+++ b/src/zeek-setup.cc
@@ -1,5 +1,7 @@
 // See the file "COPYING" in the main distribution directory for copyright.
 
+#include <unistd.h>
+
 #include "zeek/zeek-setup.h"
 
 #include "zeek/zeek-config.h"
@@ -8,7 +10,6 @@
 #include <openssl/opensslv.h>
 #include <openssl/ssl.h>
 #include <sys/types.h>
-#include <unistd.h>
 #include <csignal>
 #include <cstdio>
 #include <cstdlib>