diff --git a/src/common/windows/pdb_source_line_writer.cc b/src/common/windows/pdb_source_line_writer.cc
index 5be053dc..4266dca8 100644
--- a/src/common/windows/pdb_source_line_writer.cc
+++ b/src/common/windows/pdb_source_line_writer.cc
@@ -715,10 +715,12 @@ bool PDBSourceLineWriter::GetModuleInfo(PDBModuleInfo *info) {
       return false;
     }
 
+    // Use the same format that the MS symbol server uses in filesystem
+    // hierarchies.
     wchar_t age_string[9];
     WindowsStringUtils::safe_swprintf(
         age_string, sizeof(age_string) / sizeof(age_string[0]),
-        L"%X", age);
+        L"%x", age);
 
     info->debug_identifier = GUIDString::GUIDToSymbolServerWString(&guid);
     info->debug_identifier.append(age_string);
@@ -728,11 +730,13 @@ bool PDBSourceLineWriter::GetModuleInfo(PDBModuleInfo *info) {
       return false;
     }
 
+    // Use the same format that the MS symbol server uses in filesystem
+    // hierarchies.
     wchar_t identifier_string[17];
     WindowsStringUtils::safe_swprintf(
         identifier_string,
         sizeof(identifier_string) / sizeof(identifier_string[0]),
-        L"%08x%x", signature, age);
+        L"%08X%x", signature, age);
     info->debug_identifier = identifier_string;
   }
 
diff --git a/src/processor/minidump.cc b/src/processor/minidump.cc
index cce8549b..34796d19 100644
--- a/src/processor/minidump.cc
+++ b/src/processor/minidump.cc
@@ -1114,8 +1114,10 @@ string MinidumpModule::code_identifier() const {
   switch (raw_system_info->platform_id) {
     case MD_OS_WIN32_NT:
     case MD_OS_WIN32_WINDOWS: {
+      // Use the same format that the MS symbol server uses in filesystem
+      // hierarchies.
       char identifier_string[17];
-      snprintf(identifier_string, sizeof(identifier_string), "%08x%x",
+      snprintf(identifier_string, sizeof(identifier_string), "%08X%x",
                module_.time_date_stamp, module_.size_of_image);
       identifier = identifier_string;
       break;
@@ -1220,9 +1222,11 @@ string MinidumpModule::debug_identifier() const {
     const MDCVInfoPDB70* cv_record_70 =
         reinterpret_cast<const MDCVInfoPDB70*>(&(*cv_record_)[0]);
     if (cv_record_70->cv_signature == MD_CVINFOPDB70_SIGNATURE) {
+      // Use the same format that the MS symbol server uses in filesystem
+      // hierarchies.
       char identifier_string[41];
       snprintf(identifier_string, sizeof(identifier_string),
-               "%08X%04X%04X%02X%02X%02X%02X%02X%02X%02X%02X%X",
+               "%08X%04X%04X%02X%02X%02X%02X%02X%02X%02X%02X%x",
                cv_record_70->signature.data1,
                cv_record_70->signature.data2,
                cv_record_70->signature.data3,
@@ -1241,9 +1245,11 @@ string MinidumpModule::debug_identifier() const {
       const MDCVInfoPDB20* cv_record_20 =
           reinterpret_cast<const MDCVInfoPDB20*>(&(*cv_record_)[0]);
 
+      // Use the same format that the MS symbol server uses in filesystem
+      // hierarchies.
       char identifier_string[17];
       snprintf(identifier_string, sizeof(identifier_string),
-               "%08x%x", cv_record_20->signature, cv_record_20->age);
+               "%08X%x", cv_record_20->signature, cv_record_20->age);
       identifier = identifier_string;
     }
   }
diff --git a/src/processor/simple_symbol_supplier.h b/src/processor/simple_symbol_supplier.h
index fdfcf0ca..9995161e 100644
--- a/src/processor/simple_symbol_supplier.h
+++ b/src/processor/simple_symbol_supplier.h
@@ -36,8 +36,9 @@
 // directory with a name identical to the corresponding debugging file (pdb).
 // Within each of these directories, there are subdirectories named for the
 // debugging file's identifier.  For recent pdb files, this is a concatenation
-// of the pdb's uuid and age, presented in hexadecimal form, using uppercase
-// characters and no dashes or separators.  Within that subdirectory,
+// of the pdb's uuid and age, presented in hexadecimal form, without any
+// dashes or separators.  The uuid is in uppercase hexadecimal and the age
+// is in lowercase hexadecimal.  Within that subdirectory,
 // SimpleSymbolSupplier expects to find the symbol file, which is named
 // identically to the debug file, but with a .sym extension.  If the original
 // debug file had a name ending in .pdb, the .pdb extension will be replaced
diff --git a/src/processor/testdata/minidump2.dump.out b/src/processor/testdata/minidump2.dump.out
index 32fa6c07..c1be1be6 100644
--- a/src/processor/testdata/minidump2.dump.out
+++ b/src/processor/testdata/minidump2.dump.out
@@ -201,7 +201,7 @@ MDRawModule
   misc_record.data_size           = 0
   misc_record.rva                 = 0x0
   (code_file)                     = "C:\test_app.exe"
-  (code_identifier)               = "45787a492c000"
+  (code_identifier)               = "45787A492c000"
   (cv_record).cv_signature        = 0x53445352
   (cv_record).signature           = da006aa3-0d68-4df0-80c8-d782a2273853
   (cv_record).age                 = 1
@@ -233,7 +233,7 @@ MDRawModule
   misc_record.data_size           = 0
   misc_record.rva                 = 0x0
   (code_file)                     = "C:\WINDOWS\system32\ntdll.dll"
-  (code_identifier)               = "411096b4b0000"
+  (code_identifier)               = "411096B4b0000"
   (cv_record).cv_signature        = 0x53445352
   (cv_record).signature           = 36515fb5-d043-45e4-91f6-72fa2e2878c0
   (cv_record).age                 = 2
@@ -265,7 +265,7 @@ MDRawModule
   misc_record.data_size           = 0
   misc_record.rva                 = 0x0
   (code_file)                     = "C:\WINDOWS\system32\kernel32.dll"
-  (code_identifier)               = "44ab9a84f4000"
+  (code_identifier)               = "44AB9A84f4000"
   (cv_record).cv_signature        = 0x53445352
   (cv_record).signature           = bce8785c-57b4-4245-a669-896b6a19b954
   (cv_record).age                 = 2
@@ -297,7 +297,7 @@ MDRawModule
   misc_record.data_size           = 0
   misc_record.rva                 = 0x0
   (code_file)                     = "C:\WINDOWS\system32\ole32.dll"
-  (code_identifier)               = "42e5be9313d000"
+  (code_identifier)               = "42E5BE9313d000"
   (cv_record).cv_signature        = 0x53445352
   (cv_record).signature           = 683b65b2-46f4-4187-96d2-ee6d4c55eb11
   (cv_record).age                 = 2
@@ -329,7 +329,7 @@ MDRawModule
   misc_record.data_size           = 0
   misc_record.rva                 = 0x0
   (code_file)                     = "C:\WINDOWS\system32\advapi32.dll"
-  (code_identifier)               = "411096a79b000"
+  (code_identifier)               = "411096A79b000"
   (cv_record).cv_signature        = 0x53445352
   (cv_record).signature           = 455d6c5f-184d-45bb-b5c5-f30f82975114
   (cv_record).age                 = 2
@@ -361,7 +361,7 @@ MDRawModule
   misc_record.data_size           = 0
   misc_record.rva                 = 0x0
   (code_file)                     = "C:\WINDOWS\system32\rpcrt4.dll"
-  (code_identifier)               = "411096ae91000"
+  (code_identifier)               = "411096AE91000"
   (cv_record).cv_signature        = 0x53445352
   (cv_record).signature           = bea45a72-1da1-41da-a3ba-86b3a2031153
   (cv_record).age                 = 2
@@ -393,7 +393,7 @@ MDRawModule
   misc_record.data_size           = 0
   misc_record.rva                 = 0x0
   (code_file)                     = "C:\WINDOWS\system32\gdi32.dll"
-  (code_identifier)               = "43b34feb47000"
+  (code_identifier)               = "43B34FEB47000"
   (cv_record).cv_signature        = 0x53445352
   (cv_record).signature           = c0ea66be-00a6-4bd7-aef7-9e443a91869c
   (cv_record).age                 = 2
@@ -489,7 +489,7 @@ MDRawModule
   misc_record.data_size           = 0
   misc_record.rva                 = 0x0
   (code_file)                     = "C:\WINDOWS\system32\imm32.dll"
-  (code_identifier)               = "411096ae1d000"
+  (code_identifier)               = "411096AE1d000"
   (cv_record).cv_signature        = 0x53445352
   (cv_record).signature           = 2c17a49c-251b-4c8e-b9e2-ad13d7d9ea16
   (cv_record).age                 = 2
@@ -521,7 +521,7 @@ MDRawModule
   misc_record.data_size           = 0
   misc_record.rva                 = 0x0
   (code_file)                     = "C:\WINDOWS\system32\dbghelp.dll"
-  (code_identifier)               = "4110969aa1000"
+  (code_identifier)               = "4110969Aa1000"
   (cv_record).cv_signature        = 0x53445352
   (cv_record).signature           = 39559573-e21b-46f2-8e28-6923be9e6a76
   (cv_record).age                 = 1
@@ -553,7 +553,7 @@ MDRawModule
   misc_record.data_size           = 0
   misc_record.rva                 = 0x0
   (code_file)                     = "C:\WINDOWS\system32\version.dll"
-  (code_identifier)               = "411096b78000"
+  (code_identifier)               = "411096B78000"
   (cv_record).cv_signature        = 0x53445352
   (cv_record).signature           = 180a90c4-0384-463e-82dd-c45b2c8ab76e
   (cv_record).age                 = 2
@@ -585,7 +585,7 @@ MDRawModule
   misc_record.data_size           = 0
   misc_record.rva                 = 0x0
   (code_file)                     = "C:\WINDOWS\system32\psapi.dll"
-  (code_identifier)               = "411096cab000"
+  (code_identifier)               = "411096CAb000"
   (cv_record).cv_signature        = 0x53445352
   (cv_record).signature           = a5c3a1f9-689f-43d8-ad22-8a0929388970
   (cv_record).age                 = 2