diff --git a/extra/io/unix/freebsd/freebsd.factor b/extra/io/unix/freebsd/freebsd.factor
index 65a208c556..49fbc9af7e 100644
--- a/extra/io/unix/freebsd/freebsd.factor
+++ b/extra/io/unix/freebsd/freebsd.factor
@@ -1,3 +1,3 @@
-USING: io.backend system ;
+USING: io.unix.bsd io.backend system ;
 
 freebsd set-io-backend
diff --git a/extra/io/unix/macosx/macosx.factor b/extra/io/unix/macosx/macosx.factor
index 277a38080c..c1c73ea018 100644
--- a/extra/io/unix/macosx/macosx.factor
+++ b/extra/io/unix/macosx/macosx.factor
@@ -1,4 +1,4 @@
-USING: io.backend io.monitors io.monitors.private
+USING: io.unix.bsd io.backend io.monitors io.monitors.private
 continuations kernel core-foundation.fsevents sequences
 namespaces arrays system ;
 IN: io.unix.macosx
diff --git a/extra/io/unix/netbsd/netbsd.factor b/extra/io/unix/netbsd/netbsd.factor
index c5771c8ffc..ed134788b6 100644
--- a/extra/io/unix/netbsd/netbsd.factor
+++ b/extra/io/unix/netbsd/netbsd.factor
@@ -1,3 +1,3 @@
-USING: io.backend system ;
+USING: io.unix.bsd io.backend system ;
 
 netbsd set-io-backend
diff --git a/extra/io/unix/openbsd/openbsd.factor b/extra/io/unix/openbsd/openbsd.factor
index 1907471263..dfc466f94b 100644
--- a/extra/io/unix/openbsd/openbsd.factor
+++ b/extra/io/unix/openbsd/openbsd.factor
@@ -1,3 +1,3 @@
-USING: io.backend core-foundation.fsevents system ;
+USING: io.unix.bsd io.backend system ;
 
 openbsd set-io-backend