diff --git a/mozglue/misc/StackWalk.cpp b/mozglue/misc/StackWalk.cpp
index 7e54588c620..dbf668cbb83 100644
--- a/mozglue/misc/StackWalk.cpp
+++ b/mozglue/misc/StackWalk.cpp
@@ -817,7 +817,7 @@ MozDescribeCodeAddress(void* aPC, MozCodeAddressDetails* aDetails)
   modInfoRes = SymGetModuleInfoEspecial64(myProcess, addr, &modInfo, &lineInfo);
 
   if (modInfoRes) {
-    strncpy(aDetails->library, modInfo.ModuleName,
+    strncpy(aDetails->library, modInfo.LoadedImageName,
                 sizeof(aDetails->library));
     aDetails->library[mozilla::ArrayLength(aDetails->library) - 1] = '\0';
     aDetails->loffset = (char*)aPC - (char*)modInfo.BaseOfImage;
diff --git a/testing/tools/fileid/moz.build b/testing/tools/fileid/moz.build
index b15641bf587..701886f6650 100644
--- a/testing/tools/fileid/moz.build
+++ b/testing/tools/fileid/moz.build
@@ -4,6 +4,8 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
+GeckoProgram('fileid', linkage=None, msvcrt='static')
+
 if CONFIG['OS_ARCH'] == 'Linux':
     USE_LIBS += [
         'breakpad_linux_common_s',
@@ -25,4 +27,9 @@ if CONFIG['OS_ARCH'] == 'Linux' or CONFIG['OS_ARCH'] == 'Darwin':
     LOCAL_INCLUDES += [
         '/toolkit/crashreporter/google-breakpad/src',
     ]
-    GeckoProgram('fileid', linkage=None)
+
+if CONFIG['OS_ARCH'] == 'WINNT':
+    SOURCES += ['win_fileid.cpp']
+    OS_LIBS += ['dbghelp']
+
+NO_PGO = True
diff --git a/testing/tools/fileid/win_fileid.cpp b/testing/tools/fileid/win_fileid.cpp
new file mode 100644
index 00000000000..7151baa9238
--- /dev/null
+++ b/testing/tools/fileid/win_fileid.cpp
@@ -0,0 +1,90 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <Windows.h>
+#include <dbghelp.h>
+
+const DWORD CV_SIGNATURE_RSDS = 0x53445352; // 'SDSR'
+
+struct CV_INFO_PDB70 {
+  DWORD      CvSignature;
+  GUID       Signature;
+  DWORD      Age;
+  BYTE       PdbFileName[1];
+};
+
+void print_guid(const GUID& guid, DWORD age)
+{
+  printf("%08X%04X%04X%02X%02X%02X%02X%02X%02X%02X%02X%X",
+         guid.Data1, guid.Data2, guid.Data3,
+         guid.Data4[0], guid.Data4[1], guid.Data4[2], guid.Data4[3],
+         guid.Data4[4], guid.Data4[5], guid.Data4[6], guid.Data4[7],
+         age);
+}
+
+int main(int argc, char** argv)
+{
+  if (argc != 2) {
+    fprintf(stderr, "usage: fileid <file>\n");
+    return 1;
+  }
+
+  HANDLE file = CreateFileA(argv[1],
+                            GENERIC_READ,
+                            FILE_SHARE_READ,
+                            nullptr,
+                            OPEN_EXISTING,
+                            FILE_ATTRIBUTE_NORMAL,
+                            nullptr);
+  if (file == INVALID_HANDLE_VALUE) {
+    fprintf(stderr, "Couldn't open file: %s\n", argv[1]);
+    return 1;
+  }
+
+  HANDLE mapFile = CreateFileMappingA(file, NULL, PAGE_READONLY, 0, 0, 0);
+  if (mapFile == nullptr) {
+    fprintf(stderr, "Couldn't create file mapping\n");
+    CloseHandle(file);
+    return 1;
+  }
+
+  uint8_t* base = reinterpret_cast<uint8_t*>(MapViewOfFile(mapFile,
+                                                           FILE_MAP_READ,
+                                                           0,
+                                                           0,
+                                                           0));
+  if (base == nullptr) {
+    fprintf(stderr, "Couldn't map file\n");
+    CloseHandle(mapFile);
+    CloseHandle(file);
+    return 1;
+  }
+
+  DWORD size;
+  PIMAGE_DEBUG_DIRECTORY debug_dir =
+    reinterpret_cast<PIMAGE_DEBUG_DIRECTORY>(
+      ImageDirectoryEntryToDataEx(base,
+                                  FALSE,
+                                  IMAGE_DIRECTORY_ENTRY_DEBUG,
+                                  &size,
+                                  nullptr));
+
+  bool found = false;
+  if (debug_dir->Type == IMAGE_DEBUG_TYPE_CODEVIEW) {
+    CV_INFO_PDB70* cv =
+      reinterpret_cast<CV_INFO_PDB70*>(base + debug_dir->PointerToRawData);
+    if (cv->CvSignature == CV_SIGNATURE_RSDS) {
+      found = true;
+      print_guid(cv->Signature, cv->Age);
+    }
+  }
+
+  UnmapViewOfFile(base);
+  CloseHandle(mapFile);
+  CloseHandle(file);
+
+  return found ? 0 : 1;
+}
diff --git a/tools/rb/fix_stack_using_bpsyms.py b/tools/rb/fix_stack_using_bpsyms.py
index ed89345d1bd..156acb5882c 100755
--- a/tools/rb/fix_stack_using_bpsyms.py
+++ b/tools/rb/fix_stack_using_bpsyms.py
@@ -85,7 +85,14 @@ def findIdForPath(path):
   # We should always be packaged with a "fileid" executable.
   fileid_exe = os.path.join(here, 'fileid')
   if not os.path.isfile(fileid_exe):
-    raise Exception("Could not find fileid executable in %s" % here)
+    fileid_exe = fileid_exe + '.exe'
+    if not os.path.isfile(fileid_exe):
+      raise Exception("Could not find fileid executable in %s" % here)
+
+  if not os.path.isfile(path):
+    for suffix in ('.exe', '.dll'):
+      if os.path.isfile(path + suffix):
+        path = path + suffix
   try:
     return subprocess.check_output([fileid_exe, path]).rstrip()
   except subprocess.CalledProcessError as e:
@@ -96,11 +103,12 @@ def guessSymbolFile(full_path, symbolsDir):
   """Guess a symbol file based on an object file's basename, ignoring the path and UUID."""
   fn = os.path.basename(full_path)
   d1 = os.path.join(symbolsDir, fn)
+  root, _ = os.path.splitext(fn)
+  if os.path.exists(os.path.join(symbolsDir, root) + '.pdb'):
+    d1 = os.path.join(symbolsDir, root) + '.pdb'
+    fn = root
   if not os.path.exists(d1):
-    fn = fn + ".pdb"
-    d1 = os.path.join(symbolsDir, fn)
-    if not os.path.exists(d1):
-      return None
+    return None
   uuids = os.listdir(d1)
   if len(uuids) == 0:
     raise Exception("Missing symbol file for " + fn)
@@ -108,8 +116,6 @@ def guessSymbolFile(full_path, symbolsDir):
     uuid = findIdForPath(full_path)
   else:
     uuid = uuids[0]
-  if fn.endswith(".pdb"):
-    fn = fn[:-4]
   return os.path.join(d1, uuid, fn + ".sym")
 
 parsedSymbolFiles = {}