diff --git a/codeGenIntermediate/src/prog8/codegen/intermediate/IRPeepholeOptimizer.kt b/codeGenIntermediate/src/prog8/codegen/intermediate/IRPeepholeOptimizer.kt
index 462a8f447..58cba81a5 100644
--- a/codeGenIntermediate/src/prog8/codegen/intermediate/IRPeepholeOptimizer.kt
+++ b/codeGenIntermediate/src/prog8/codegen/intermediate/IRPeepholeOptimizer.kt
@@ -99,8 +99,11 @@ internal class IRPeepholeOptimizer(private val irprog: IRProgram) {
         val chunks = mutableListOf<IRCodeChunkBase>()
         chunks += sub.chunks[0]
         for(ix in 1 until sub.chunks.size) {
-            if(mayJoin(chunks.last(), sub.chunks[ix]))
-                chunks.last().instructions += sub.chunks[ix].instructions
+            val lastChunk = chunks.last()
+            if(mayJoin(lastChunk, sub.chunks[ix])) {
+                lastChunk.instructions += sub.chunks[ix].instructions
+                lastChunk.next = sub.chunks[ix].next
+            }
             else
                 chunks += sub.chunks[ix]
         }
diff --git a/docs/source/todo.rst b/docs/source/todo.rst
index 933aaf6af..00f8ada95 100644
--- a/docs/source/todo.rst
+++ b/docs/source/todo.rst
@@ -3,8 +3,6 @@ TODO
 
 For next release
 ^^^^^^^^^^^^^^^^
-- ir: join more codechunks, before ir is written to file
-- ir: fix removeWeirdBranches in IR optimizer
 - update diagram in technical.rst?
 
 ...
diff --git a/intermediate/src/prog8/intermediate/IRProgram.kt b/intermediate/src/prog8/intermediate/IRProgram.kt
index f5f3d1de0..a5f28a83d 100644
--- a/intermediate/src/prog8/intermediate/IRProgram.kt
+++ b/intermediate/src/prog8/intermediate/IRProgram.kt
@@ -100,7 +100,7 @@ class IRProgram(val name: String,
                             // no jump at the end, so link to next chunk (if it exists)
                             val next = nextChunk()
                             if(next!=null) {
-                                if (next is IRCodeChunk)
+                                if (next is IRCodeChunk && chunk.instructions.lastOrNull()?.opcode !in OpcodesThatJump)
                                     chunk.next = next
                                 else
                                     throw AssemblyError("code chunk flows into following non-code chunk")
@@ -144,8 +144,16 @@ class IRProgram(val name: String,
                     require(sub.chunks.first().label == sub.name) { "first chunk in subroutine should have sub name as its label" }
                 }
                 sub.chunks.forEach { chunk ->
-                    if (chunk is IRCodeChunk)
-                        require(chunk.instructions.isNotEmpty() || chunk.label!=null)
+                    if (chunk is IRCodeChunk) {
+                        require(chunk.instructions.isNotEmpty() || chunk.label != null)
+                        if(chunk.instructions.lastOrNull()?.opcode in OpcodesThatJump)
+                            require(chunk.next == null) { "chunk ending with a jump shouldn't be linked to next" }
+                        else {
+                            // if chunk is NOT the last in the block, it needs to link to next.
+                            val isLast = sub.chunks.last() === chunk
+                            require(isLast || chunk.next != null) { "chunk needs to be linked to next" }
+                        }
+                    }
                     else
                         require(chunk.instructions.isEmpty())
                     chunk.instructions.forEach {