diff --git a/llvm/lib/Target/WebAssembly/InstPrinter/WebAssemblyInstPrinter.cpp b/llvm/lib/Target/WebAssembly/InstPrinter/WebAssemblyInstPrinter.cpp
index e26cf1d8cf4f..33b224adc6e2 100644
--- a/llvm/lib/Target/WebAssembly/InstPrinter/WebAssemblyInstPrinter.cpp
+++ b/llvm/lib/Target/WebAssembly/InstPrinter/WebAssemblyInstPrinter.cpp
@@ -85,14 +85,12 @@ void WebAssemblyInstPrinter::printInst(const MCInst *MI, raw_ostream &OS,
       break;
     case WebAssembly::END_LOOP:
     case WebAssembly::END_LOOP_S:
-      if (ControlFlowStack.empty())
-        report_fatal_error("End marker mismatch!");
+      assert(!ControlFlowStack.empty() && "End marker mismatch!");
       ControlFlowStack.pop_back();
       break;
     case WebAssembly::END_BLOCK:
     case WebAssembly::END_BLOCK_S:
-      if (ControlFlowStack.empty())
-        report_fatal_error("END marker mismatch!");
+      assert(!ControlFlowStack.empty() && "End marker mismatch!");
       printAnnotation(
           OS, "label" + utostr(ControlFlowStack.pop_back_val().first) + ':');
       break;
diff --git a/llvm/test/CodeGen/WebAssembly/block-mismatch.mir b/llvm/test/CodeGen/WebAssembly/block-mismatch.mir
deleted file mode 100644
index 0da58e9ddb82..000000000000
--- a/llvm/test/CodeGen/WebAssembly/block-mismatch.mir
+++ /dev/null
@@ -1,18 +0,0 @@
-# RUN: not llc -mtriple=wasm32-unknown-unknown -start-after xray-instrumentation %s -o /dev/null 2>&1 | FileCheck %s
-
-# This tests if there are block/loop marker mismatches, the program crashes.
-
----
-name: block_mismatch
-liveins:
-  - { reg: '$arguments', reg: '$value_stack' }
-tracksRegLiveness: true
-body: |
-  bb.0:
-    liveins: $arguments, $value_stack
-    BLOCK 64, implicit-def $value_stack, implicit $value_stack
-    END_BLOCK implicit-def $value_stack, implicit $value_stack
-    ; CHECK: LLVM ERROR: END marker mismatch!
-    END_BLOCK implicit-def $value_stack, implicit $value_stack
-    RETURN_VOID implicit-def dead $arguments
-...
diff --git a/llvm/test/MC/WebAssembly/block-mismatch.s b/llvm/test/MC/WebAssembly/block-mismatch.s
new file mode 100644
index 000000000000..586407a054ab
--- /dev/null
+++ b/llvm/test/MC/WebAssembly/block-mismatch.s
@@ -0,0 +1,13 @@
+# RUN: not llvm-mc -triple=wasm32-unknown-unknown %s -o - 2>&1 | FileCheck %s
+
+# This tests if there are block/loop marker mismatches, the program crashes.
+  .text
+  .type  test0,@function
+test0:
+  block
+  end_block
+  # CHECK: End marker mismatch!
+  end_block
+  end_function
+.Lfunc_end1:
+  .size  test1, .Lfunc_end1-test1