diff --git a/lib/dns/tests/geoip_test.c b/lib/dns/tests/geoip_test.c
index c73a159228e1256a2e1db2bc3296b7d4e24989d2..06ca0a830c4f6551b35ae7e76e2061889e3dbc22 100644
--- a/lib/dns/tests/geoip_test.c
+++ b/lib/dns/tests/geoip_test.c
@@ -17,6 +17,7 @@
 #include <unistd.h>
 
 #include <isc/print.h>
+#include <isc/string.h>
 #include <isc/types.h>
 
 #include <dns/geoip.h>
diff --git a/lib/dns/tests/master_test.c b/lib/dns/tests/master_test.c
index 0cb31ef39bf4e9a81cd2e631ea6a42957bae1f35..2115fb3296e15f4940919bba99e0ab386c4c8fd7 100644
--- a/lib/dns/tests/master_test.c
+++ b/lib/dns/tests/master_test.c
@@ -18,6 +18,7 @@
 #include <unistd.h>
 
 #include <isc/print.h>
+#include <isc/string.h>
 #include <isc/xml.h>
 
 #include <dns/cache.h>
diff --git a/lib/isc/inet_ntop.c b/lib/isc/inet_ntop.c
index f2c65584aa71ede5a62d7db14035f45ea0299b42..487a3352761e5ef21f3ce6c0772a0c2d47263dad 100644
--- a/lib/isc/inet_ntop.c
+++ b/lib/isc/inet_ntop.c
@@ -21,6 +21,7 @@ static char rcsid[] =
 
 #include <isc/net.h>
 #include <isc/print.h>
+#include <isc/string.h>
 
 #define NS_INT16SZ	 2
 #define NS_IN6ADDRSZ	16
diff --git a/lib/isc/unix/entropy.c b/lib/isc/unix/entropy.c
index bce15d8d10c87032117ae34e637f73c4c759ec1f..559b034b1c0601dc4f6b7b9161aadaea245dfea8 100644
--- a/lib/isc/unix/entropy.c
+++ b/lib/isc/unix/entropy.c
@@ -29,6 +29,7 @@
 
 #include <isc/platform.h>
 #include <isc/strerror.h>
+#include <isc/string.h>
 
 #ifdef ISC_PLATFORM_NEEDSYSSELECTH
 #include <sys/select.h>
diff --git a/lib/isc/win32/dir.c b/lib/isc/win32/dir.c
index f1003aa61d17b367f3ad75a70b80fdec609ae571..4b0ad914559026d4862bfdea5ab1603f69534bcb 100644
--- a/lib/isc/win32/dir.c
+++ b/lib/isc/win32/dir.c
@@ -19,9 +19,10 @@
 
 #include <sys/stat.h>
 
+#include <isc/assertions.h>
 #include <isc/dir.h>
 #include <isc/magic.h>
-#include <isc/assertions.h>
+#include <isc/string.h>
 #include <isc/util.h>
 
 #include "errno2result.h"
diff --git a/lib/isc/win32/fsaccess.c b/lib/isc/win32/fsaccess.c
index e61d72e1ef2639856af81ab157290cd0d7f00363..8b931034a634da3699f667331558cbaef4a56989 100644
--- a/lib/isc/win32/fsaccess.c
+++ b/lib/isc/win32/fsaccess.c
@@ -29,6 +29,7 @@
 
 #include <isc/file.h>
 #include <isc/stat.h>
+#include <isc/string.h>
 
 #include "errno2result.h"
 
diff --git a/lib/isc/win32/ntpaths.c b/lib/isc/win32/ntpaths.c
index d9e997ea3ad0129440bf40a377892aba81a9059e..5c08599280d1834d5fdf294b57885e1014f8885f 100644
--- a/lib/isc/win32/ntpaths.c
+++ b/lib/isc/win32/ntpaths.c
@@ -17,8 +17,10 @@
  */
 
 #include <config.h>
+
 #include <isc/bind_registry.h>
 #include <isc/ntpaths.h>
+#include <isc/string.h>
 
 /*
  * Module Variables