--- a/js/src/vm/Printer.cpp
+++ b/js/src/vm/Printer.cpp
@@ -13,16 +13,20 @@
 #include <stdarg.h>
 #include <stdio.h>
 
 #include "jscntxt.h"
 #include "jsutil.h"
 
 #include "ds/LifoAlloc.h"
 
+#ifdef XP_WIN32
+#include "jswin.h"
+#endif
+
 using mozilla::PodCopy;
 
 namespace
 {
 
 class GenericPrinterPrintfTarget : public mozilla::PrintfTarget
 {
 public:
@@ -445,16 +449,28 @@ bool
 Fprinter::put(const char* s, size_t len)
 {
     MOZ_ASSERT(file_);
     int i = fwrite(s, /*size=*/ 1, /*nitems=*/ len, file_);
     if (size_t(i) != len) {
         reportOutOfMemory();
         return false;
     }
+#ifdef XP_WIN32
+    if ((file_ == stderr) && (IsDebuggerPresent())) {
+        UniqueChars buf(static_cast<char*>(js_malloc(len + 1)));
+        if (!buf) {
+            reportOutOfMemory();
+            return false;
+        }
+        PodCopy(buf.get(), s, len);
+        buf[len] = '\0';
+        OutputDebugStringA(buf.get());
+    }
+#endif
     return true;
 }
 
 LSprinter::LSprinter(LifoAlloc* lifoAlloc)
   : alloc_(lifoAlloc),
     head_(nullptr),
     tail_(nullptr),
     unused_(0)