diff --git a/blk/004 b/blk/004
index aea982b..b50a1e8 100644
--- a/blk/004
+++ b/blk/004
@@ -1 +1,2 @@
 21 How blocks are organized    22 Addressed devices
+23 Branching
diff --git a/blk/023 b/blk/023
new file mode 100644
index 0000000..de7059b
--- /dev/null
+++ b/blk/023
@@ -0,0 +1,11 @@
+Branching
+
+Branching in Collapse OS is limited to 8-bit. This represents
+64 word references forward or backward. While this might seem
+a bit tight at first, having this limit saves us a non-
+negligible amount of resource usage.
+
+The reasoning behind this intentional limit is that huge
+branches are generally a indicator that a logic ought to be
+simplified. So here's one more constraint for you to help you
+towards simplicity.
diff --git a/blk/397 b/blk/397
index 80dd387..14955f4 100644
--- a/blk/397
+++ b/blk/397
@@ -1,6 +1,7 @@
 ( Now we have "as late as possible" stuff )
+: _bchk DUP 0x7f + 0xff > IF LIT< br-ovfl (print) ABORT THEN ;
 : DO COMPILE 2>R H@ ; IMMEDIATE
-: LOOP COMPILE (loop) H@ - , ; IMMEDIATE
+: LOOP COMPILE (loop) H@ - _bchk , ; IMMEDIATE
 ( LEAVE is implemented in low xcomp )
 : LITN 32 , , ( 32 == NUMBER ) ;
 ( gets its name at the very end. can't comment afterwards )
diff --git a/blk/398 b/blk/398
index 77d6f42..fcf0395 100644
--- a/blk/398
+++ b/blk/398
@@ -1,14 +1,13 @@
-: IF                ( -- a | a: br cell addr )
+: IF ( -- a | a: br cell addr )
     COMPILE (?br) H@ 2 ALLOT ( br cell allot )
 ; IMMEDIATE
-: THEN              ( a -- | a: br cell addr )
-    DUP H@ -^ SWAP ( a-H a ) !
+: THEN ( a -- | a: br cell addr )
+    DUP H@ -^ _bchk SWAP ( a-H a ) !
 ; IMMEDIATE
-: ELSE              ( a1 -- a2 | a1: IF cell a2: ELSE cell )
+: ELSE ( a1 -- a2 | a1: IF cell a2: ELSE cell )
     COMPILE (br)
     2 ALLOT
-    DUP H@ -^ SWAP  ( a-H a )
-    !
-    H@ 2-          ( push a. -2 for allot offset )
+    [COMPILE] THEN
+    H@ 2- ( push a. -2 for allot offset )
 ; IMMEDIATE
 
diff --git a/blk/399 b/blk/399
index 0f2a5e5..e0befb6 100644
--- a/blk/399
+++ b/blk/399
@@ -1,6 +1,6 @@
 : BEGIN H@ ; IMMEDIATE
-: AGAIN COMPILE (br) H@ - , ; IMMEDIATE
-: UNTIL COMPILE (?br) H@ - , ; IMMEDIATE
+: AGAIN COMPILE (br) H@ - _bchk , ; IMMEDIATE
+: UNTIL COMPILE (?br) H@ - _bchk , ; IMMEDIATE
 : [ INTERPRET ; IMMEDIATE
 : ] R> DROP ;
 : LIT< WORD 34 , SCPY 0 C, ; IMMEDIATE
diff --git a/emul/forth.bin b/emul/forth.bin
index 13b327d..221c9e2 100644
Binary files a/emul/forth.bin and b/emul/forth.bin differ