1 files changed, 6 insertions, 9 deletions
diff --git a/src/passes/MergeBlocks.cpp b/src/passes/MergeBlocks.cpp
index 3627a5b0e..1ef34117e 100644
--- a/src/passes/MergeBlocks.cpp
+++ b/src/passes/MergeBlocks.cpp
@@ -214,21 +214,18 @@ static void optimizeBlock(Block* curr, Module* module, PassOptions& passOptions)
       }
       if (!child) continue;
       if (child->name.is()) continue; // named blocks can have breaks to them (and certainly do, if we ran RemoveUnusedNames and RemoveUnusedBrs)
-      if (child->type == unreachable) {
-        // an unreachable block can have a concrete final element (which is never reached)
-        if (!child->list.empty()) {
-          if (isConcreteWasmType(child->list.back()->type)) {
-            // just remove it
-            child->list.pop_back();
-          }
-        }
-      }
       ExpressionList merged(module->allocator);
       for (size_t j = 0; j < i; j++) {
         merged.push_back(curr->list[j]);
       }
       for (auto item : child->list) {
         merged.push_back(item);
+        if (item->type == unreachable) {
+          // we don't need anything else from the child,
+          // and it is always valid to end on an unreachable,
+          // so stop there (otherwise, we need to be careful)
+          break;
+        }
       }
       for (size_t j = i + 1; j < curr->list.size(); j++) {
         merged.push_back(curr->list[j]);