diff --git a/basis/compiler/cfg/def-use/def-use.factor b/basis/compiler/cfg/def-use/def-use.factor
index 28351ca7b2..1484b3ec72 100644
--- a/basis/compiler/cfg/def-use/def-use.factor
+++ b/basis/compiler/cfg/def-use/def-use.factor
@@ -51,10 +51,10 @@ M: ##alien-getter uses-vregs src>> 1array ;
 M: ##alien-setter uses-vregs [ src>> ] [ value>> ] bi 2array ;
 M: ##fixnum-overflow uses-vregs [ src1>> ] [ src2>> ] bi 2array ;
 M: ##phi uses-vregs inputs>> ;
+M: ##gc uses-vregs live-in>> ;
 M: _conditional-branch uses-vregs [ src1>> ] [ src2>> ] bi 2array ;
 M: _compare-imm-branch uses-vregs src1>> 1array ;
 M: _dispatch uses-vregs src>> 1array ;
-M: _gc uses-vregs live-in>> ;
 M: insn uses-vregs drop f ;
 
 ! Instructions that use vregs
@@ -66,7 +66,8 @@ UNION: vreg-insn
 ##fixnum-overflow
 ##conditional-branch
 ##compare-imm-branch
+##phi
+##gc
 _conditional-branch
 _compare-imm-branch
-_dispatch
-_gc ;
+_dispatch ;
diff --git a/basis/compiler/cfg/gc-checks/gc-checks.factor b/basis/compiler/cfg/gc-checks/gc-checks.factor
index 7a47da00a8..91e79ea2dd 100644
--- a/basis/compiler/cfg/gc-checks/gc-checks.factor
+++ b/basis/compiler/cfg/gc-checks/gc-checks.factor
@@ -14,7 +14,7 @@ IN: compiler.cfg.gc-checks
 : insert-gc-check ( basic-block -- )
     dup gc? [
         dup
-        [ swap object-pointer-regs \ _gc new-insn suffix ]
+        [ swap object-pointer-regs \ ##gc new-insn prefix ]
         change-instructions drop
     ] [ drop ] if ;
 
diff --git a/basis/compiler/cfg/instructions/instructions.factor b/basis/compiler/cfg/instructions/instructions.factor
index d2d444a4a5..314a66ba9c 100644
--- a/basis/compiler/cfg/instructions/instructions.factor
+++ b/basis/compiler/cfg/instructions/instructions.factor
@@ -223,14 +223,14 @@ INSN: ##compare-imm < ##binary-imm cc temp ;
 INSN: ##compare-float-branch < ##conditional-branch ;
 INSN: ##compare-float < ##binary cc temp ;
 
+INSN: ##gc live-in ;
+
 ! Instructions used by machine IR only.
 INSN: _prologue stack-frame ;
 INSN: _epilogue stack-frame ;
 
 INSN: _label id ;
 
-INSN: _gc live-in ;
-
 INSN: _branch label ;
 
 INSN: _dispatch src temp ;
diff --git a/basis/compiler/cfg/stack-frame/stack-frame.factor b/basis/compiler/cfg/stack-frame/stack-frame.factor
index d545b6d15c..fd11260f97 100644
--- a/basis/compiler/cfg/stack-frame/stack-frame.factor
+++ b/basis/compiler/cfg/stack-frame/stack-frame.factor
@@ -32,8 +32,8 @@ M: insn compute-stack-frame*
         frame-required? on
     ] when ;
 
-\ _gc t frame-required? set-word-prop
 \ _spill t frame-required? set-word-prop
+\ ##gc t frame-required? set-word-prop
 \ ##fixnum-add t frame-required? set-word-prop
 \ ##fixnum-sub t frame-required? set-word-prop
 \ ##fixnum-mul t frame-required? set-word-prop