diff --git a/basis/compiler/cfg/builder/blocks/blocks.factor b/basis/compiler/cfg/builder/blocks/blocks.factor
index 96b4ed0488..b58ae2de44 100644
--- a/basis/compiler/cfg/builder/blocks/blocks.factor
+++ b/basis/compiler/cfg/builder/blocks/blocks.factor
@@ -11,10 +11,10 @@ SLOT: out-d
     dup begin-local-analysis instructions>> building set ;
 
 : end-basic-block ( block -- )
-    [ end-local-analysis ] when* building off ;
+    end-local-analysis building off ;
 
 : (begin-basic-block) ( block -- block' )
-    <basic-block> swap [ over connect-bbs ] when* dup set-basic-block ;
+    <basic-block> dup set-basic-block [ connect-bbs ] keep ;
 
 : begin-basic-block ( block -- block' )
     dup end-basic-block (begin-basic-block) ;
@@ -54,6 +54,6 @@ SLOT: out-d
     sift [ f ] [
         dup first second height-state set
         [ first ] map
-        f begin-basic-block
+        <basic-block> dup set-basic-block
         [ connect-Nto1-bbs ] keep
     ] if-empty ;
diff --git a/basis/compiler/cfg/builder/builder-tests.factor b/basis/compiler/cfg/builder/builder-tests.factor
index 158836f85a..00095c3c39 100644
--- a/basis/compiler/cfg/builder/builder-tests.factor
+++ b/basis/compiler/cfg/builder/builder-tests.factor
@@ -335,7 +335,9 @@ SYMBOL: foo
 {
     V{ T{ ##call { word set-slot } } T{ ##branch } }
 } [
-    [ f call-node-1 emit-node ] V{ } make drop
+    [
+         <basic-block> dup set-basic-block call-node-1 emit-node
+    ] V{ } make drop
     predecessors>> first instructions>>
 ] cfg-unit-test