diff --git a/runtime/vm/compiler/assembler/disassembler.cc b/runtime/vm/compiler/assembler/disassembler.cc
index d252cc016e9..27f95af5093 100644
--- a/runtime/vm/compiler/assembler/disassembler.cc
+++ b/runtime/vm/compiler/assembler/disassembler.cc
@@ -456,6 +456,10 @@ void Disassembler::DisassembleCode(const Function& function,
   if (code.IsUnknownDartCode()) {
     return;
   }
+  if (Log::Current() == Log::NoOpLog()) {
+    // Output for this isolate will be shallowed, so don't bother generating it.
+    return;
+  }
   TextBuffer buffer(128);
   const char* function_fullname = function.ToFullyQualifiedCString();
   buffer.Printf("%s", Function::KindToCString(function.kind()));
@@ -470,6 +474,10 @@ void Disassembler::DisassembleCode(const Function& function,
 }
 
 void Disassembler::DisassembleStub(const char* name, const Code& code) {
+  if (Log::Current() == Log::NoOpLog()) {
+    // Output for this isolate will be shallowed, so don't bother generating it.
+    return;
+  }
   LogBlock lb;
   THR_Print("Code for stub '%s': {\n", name);
   DisassembleToStdout formatter;