diff --git a/clients/tools/ldapmodify.c b/clients/tools/ldapmodify.c
index 33b364caae..3d4d9e9d4c 100644
--- a/clients/tools/ldapmodify.c
+++ b/clients/tools/ldapmodify.c
@@ -4,8 +4,8 @@
 
 #include <stdio.h>
 #include <stdlib.h>
-#include <ctype.h>
 
+#include <ac/ctype.h>
 #include <ac/string.h>
 #include <ac/unistd.h>
 
diff --git a/clients/tools/ldapmodrdn.c b/clients/tools/ldapmodrdn.c
index 8726004546..e293fc530e 100644
--- a/clients/tools/ldapmodrdn.c
+++ b/clients/tools/ldapmodrdn.c
@@ -4,8 +4,8 @@
 
 #include <stdio.h>
 #include <stdlib.h>
-#include <ctype.h>
 
+#include <ac/ctype.h>
 #include <ac/string.h>
 #include <ac/unistd.h>
 
diff --git a/clients/tools/ldapsearch.c b/clients/tools/ldapsearch.c
index 9fe3bdb218..18ea706c0b 100644
--- a/clients/tools/ldapsearch.c
+++ b/clients/tools/ldapsearch.c
@@ -2,8 +2,8 @@
 
 #include <stdio.h>
 #include <stdlib.h>
-#include <ctype.h>
 
+#include <ac/ctype.h>
 #include <ac/string.h>
 #include <ac/unistd.h>