diff --git a/extra/chipmunk/ffi/ffi.factor b/extra/chipmunk/ffi/ffi.factor
index f28b0467b6..9608453a2f 100644
--- a/extra/chipmunk/ffi/ffi.factor
+++ b/extra/chipmunk/ffi/ffi.factor
@@ -530,7 +530,7 @@ TYPED: cpArbiterGetNormal ( arb: cpArbiter i -- n: cpVect )
         [ contacts>> swap void* <c-direct-array> ] bi nth cpContact memory>struct n>>
     ]
     [
-        drop swappedColl>> 0 = [ ] [ cpvneg ] if
+        drop swappedColl>> 0 = [ cpvneg ] unless
     ] 2bi ; inline
 
 TYPED: cpArbiterGetPoint ( arb: cpArbiter i -- p: cpVect )
diff --git a/extra/readline/readline.factor b/extra/readline/readline.factor
index 6ce6a1cf9b..53f31b0b3d 100644
--- a/extra/readline/readline.factor
+++ b/extra/readline/readline.factor
@@ -10,7 +10,7 @@ IN: readline
     [
         readline.ffi:readline [
             |free utf8 alien>string [
-                [ ] [ readline.ffi:add_history ] if-empty
+                [ readline.ffi:add_history ] unless-empty
             ] keep
         ] [ f ] if*
     ] with-destructors ;
diff --git a/extra/roles/roles.factor b/extra/roles/roles.factor
index 3a58be9830..46da7fb549 100644
--- a/extra/roles/roles.factor
+++ b/extra/roles/roles.factor
@@ -20,7 +20,8 @@ PREDICATE: role < mixin-class
     } case ;
 
 : slot-name ( name/array -- name )
-    dup string? [ ] [ first ] if ;
+    dup string? [ first ] unless ;
+
 : slot-names ( array -- names )
     [ slot-name ] map ;
 
diff --git a/extra/site-watcher/site-watcher.factor b/extra/site-watcher/site-watcher.factor
index f0e086343e..2c3bed7812 100644
--- a/extra/site-watcher/site-watcher.factor
+++ b/extra/site-watcher/site-watcher.factor
@@ -34,7 +34,7 @@ SYMBOL: running-site-watcher
     send-site-email ;
 
 : send-reports ( seq -- )
-    [ ] [ [ send-report ] each ] if-empty ;
+    [ [ send-report ] each ] unless-empty ;
 
 PRIVATE>
 
diff --git a/extra/smalltalk/classes/classes.factor b/extra/smalltalk/classes/classes.factor
index 1798aad961..633167c4a0 100644
--- a/extra/smalltalk/classes/classes.factor
+++ b/extra/smalltalk/classes/classes.factor
@@ -13,7 +13,7 @@ classes [ H{ } clone ] initialize
 ERROR: no-class name ;
 
 : lookup-class ( class -- class )
-    classes get ?at [ ] [ no-class ] if ;
+    classes get ?at [ no-class ] unless ;
 
 : define-class ( class superclass ivars -- class-word )
     [ create-class ] [ lookup-class ] [ ] tri*
@@ -22,4 +22,4 @@ ERROR: no-class name ;
 : define-foreign ( class name -- )
     classes get set-at ;
 
-tuple "Object" define-foreign
\ No newline at end of file
+tuple "Object" define-foreign