diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp
--- a/llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp
@@ -277,11 +277,19 @@
 #endif
     }
 
-    // All previously inserted BLOCK/TRY markers should be after the BLOCK
-    // because they are all nested blocks.
+    // If there is a previously placed BLOCK/TRY marker and its corresponding
+    // END marker is before the current BLOCK's END marker, that should be
+    // placed after this BLOCK. Otherwise it should be placed before this BLOCK
+    // marker.
     if (MI.getOpcode() == WebAssembly::BLOCK ||
-        MI.getOpcode() == WebAssembly::TRY)
-      AfterSet.insert(&MI);
+        MI.getOpcode() == WebAssembly::TRY) {
+      if (BeginToEnd[&MI]->getParent()->getNumber() <= MBB.getNumber())
+        AfterSet.insert(&MI);
+#ifndef NDEBUG
+      else
+        BeforeSet.insert(&MI);
+#endif
+    }
 
 #ifndef NDEBUG
     // All END_(BLOCK|LOOP|TRY) markers should be before the BLOCK.
@@ -866,6 +874,10 @@
   // In new CFG, <destination to branch to, register containing exnref>
   DenseMap<MachineBasicBlock *, unsigned> BrDestToExnReg;
 
+  // Destinations for branches that will be newly added, for which a new
+  // BLOCK/END_BLOCK markers are necessary.
+  SmallVector<MachineBasicBlock *, 8> BrDests;
+
   // Gather possibly throwing calls (i.e., previously invokes) whose current
   // unwind destination is not the same as the original CFG.
   for (auto &MBB : reverse(MF)) {
@@ -1075,6 +1087,7 @@
                         ? DebugLoc()
                         : EHPadLayoutPred->rbegin()->getDebugLoc();
       BuildMI(EHPadLayoutPred, DL, TII.get(WebAssembly::BR)).addMBB(Cont);
+      BrDests.push_back(Cont);
     }
   }
 
@@ -1178,8 +1191,16 @@
 
       // Fix predecessor-successor relationship.
       NestedCont->transferSuccessors(MBB);
-      if (EHPad)
+      if (EHPad) {
         NestedCont->removeSuccessor(EHPad);
+        // If EHPad does not have any predecessors left after removing
+        // NextedCont predecessor, remove its successor too, because this EHPad
+        // is not reachable from the entry BB anyway. We can't remove EHPad BB
+        // itself because it can contain 'catch' or 'end', which are necessary
+        // for keeping try-catch-end structure.
+        if (EHPad->pred_empty())
+          EHPad->removeSuccessor(BrDest);
+      }
       MBB->addSuccessor(NestedEHPad);
       MBB->addSuccessor(NestedCont);
       NestedEHPad->addSuccessor(BrDest);
@@ -1211,10 +1232,14 @@
   // Recompute the dominator tree.
   getAnalysis<MachineDominatorTree>().runOnMachineFunction(MF);
 
-  // Place block markers for newly added branches.
-  SmallVector <MachineBasicBlock *, 8> BrDests;
-  for (auto &P : BrDestToTryRanges)
-    BrDests.push_back(P.first);
+  // Place block markers for newly added branches, if necessary.
+
+  // If we've created an appendix BB and a branch to it, place a block/end_block
+  // marker for that. For some new branches, those branch destination BBs start
+  // with a hoisted end_try marker, so we don't need a new marker there.
+  if (AppendixBB)
+    BrDests.push_back(AppendixBB);
+
   llvm::sort(BrDests,
              [&](const MachineBasicBlock *A, const MachineBasicBlock *B) {
                auto ANum = A->getNumber();
diff --git a/llvm/test/CodeGen/WebAssembly/cfg-stackify-eh.ll b/llvm/test/CodeGen/WebAssembly/cfg-stackify-eh.ll
--- a/llvm/test/CodeGen/WebAssembly/cfg-stackify-eh.ll
+++ b/llvm/test/CodeGen/WebAssembly/cfg-stackify-eh.ll
@@ -850,8 +850,51 @@
   unreachable
 }
 
+; We don't need to call placeBlockMarker after fixUnwindMismatches unless the
+; destination is the appendix BB at the very end. This should not crash.
+define void @test16(i32* %p, i32 %a, i32 %b) personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) {
+entry:
+  br label %loop
+
+loop:
+  invoke void @foo()
+          to label %bb0 unwind label %catch.dispatch0
+
+bb0:
+  %cmp = icmp ne i32 %a, %b
+  br i1 %cmp, label %bb1, label %last
+
+bb1:                                              ; preds = %bb0
+  invoke void @bar()
+          to label %try.cont unwind label %catch.dispatch1
+
+catch.dispatch0:                                  ; preds = %loop
+  %0 = catchswitch within none [label %catch.start0] unwind to caller
+
+catch.start0:                                     ; preds = %catch.dispatch0
+  %1 = catchpad within %0 [i8* null]
+  %2 = call i8* @llvm.wasm.get.exception(token %1)
+  %3 = call i32 @llvm.wasm.get.ehselector(token %1)
+  catchret from %1 to label %try.cont
+
+catch.dispatch1:                                  ; preds = %bb1
+  %4 = catchswitch within none [label %catch.start1] unwind to caller
+
+catch.start1:                                     ; preds = %catch.dispatch1
+  %5 = catchpad within %4 [i8* null]
+  %6 = call i8* @llvm.wasm.get.exception(token %5)
+  %7 = call i32 @llvm.wasm.get.ehselector(token %5)
+  catchret from %5 to label %try.cont
+
+try.cont:                                         ; preds = %catch.start, %loop
+  br label %loop
+
+last:
+  ret void
+}
+
 ; Check if the unwind destination mismatch stats are correct
-; NOSORT-STAT: 15 wasm-cfg-stackify    - Number of EH pad unwind mismatches found
+; NOSORT-STAT: 16 wasm-cfg-stackify    - Number of EH pad unwind mismatches found
 
 declare void @foo()
 declare void @bar()