diff --git a/blk/816 b/blk/816
index 2db7339..8cc605b 100644
--- a/blk/816
+++ b/blk/816
@@ -1,13 +1,9 @@
 lblnext BSET PC 0x1d - ORG @ 0x1b + ! ( next )
+    ( RSP check )
+    AX RS_ADDR MOVxI, BP AX CMPxx,
+    IFC, ( BP < RS_ADDR )
+        DI 0x06 MOVxm, JMPs, L1 FWRs ( execute )
+    THEN,
     DI DX MOVxx, ( <-- IP ) DX INCx, DX INCx,
     DI [DI] MOVx[], ( wordref )
-    ( continue to execute )
-lblexec BSET PC 0x36 - ORG @ 0x34 + ! ( DI -> wordref )
-    AL [DI] MOVr[], DI INCx, ( PFA )
-    AL AL ORrr, IFZ, DI JMPr, THEN, ( native )
-    AL DECr, IFNZ, ( cell or does )
-        DI PUSHx, ( push PFA )
-        AL DECr, IFZ, ( cell ) JMPs, lblnext @ RPCs, THEN,
-        ( does, see B302 )
-        DI INCx, DI INCx, DI [DI] MOVx[],
-    THEN, ( continue to compiled                        cont. )
+    ( continue to execute ) L1 FSET
diff --git a/blk/817 b/blk/817
index c2ee308..b9c83a3 100644
--- a/blk/817
+++ b/blk/817
@@ -1,11 +1,15 @@
-( compiled )
+lblexec BSET PC 0x36 - ORG @ 0x34 + ! ( DI -> wordref )
+    AL [DI] MOVr[], DI INCx, ( PFA )
+    AL AL ORrr, IFZ, DI JMPr, THEN, ( native )
+    AL DECr, IFNZ, ( cell or does )
+        DI PUSHx, ( push PFA )
+        AL DECr, IFZ, ( cell ) JMPs, lblnext @ RPCs, THEN,
+        ( does, see B302 )
+        DI INCx, DI INCx, DI [DI] MOVx[],
+    THEN, ( continue to compiled )
+    ( compiled )
     BP INCx, BP INCx, [BP] 0 DX MOV[]+x, ( pushRS )
     DX DI MOVxx, DX INCx, DX INCx, ( --> IP )
     DI [DI] MOVx[],
     JMPs, lblexec @ RPCs,
 
-lblchkPS BSET ( CX -> expected size )
-    AX PS_ADDR MOVxI, AX SP SUBxx, 2 SUBAXI, ( CALL adjust )
-    AX CX SUBxx,
-    IFNC, ( we're good ) RETn, THEN,
-    ( underflow ) DI 0x06 MOVxm, JMPs, lblexec @ RPCs,
diff --git a/blk/818 b/blk/818
new file mode 100644
index 0000000..7c36afe
--- /dev/null
+++ b/blk/818
@@ -0,0 +1,5 @@
+lblchkPS BSET ( CX -> expected size )
+    AX PS_ADDR MOVxI, AX SP SUBxx, 2 SUBAXI, ( CALL adjust )
+    AX CX CMPxx,
+    IFNC, ( we're good ) RETn, THEN,
+    ( underflow ) DI 0x06 MOVxm, JMPs, lblexec @ RPCs,