diff --git a/schemas/telemetry/modules/modules.4.parquetmr.txt b/schemas/telemetry/modules/modules.4.parquetmr.txt
index 95f3ded0a..6187a5f1d 100644
--- a/schemas/telemetry/modules/modules.4.parquetmr.txt
+++ b/schemas/telemetry/modules/modules.4.parquetmr.txt
@@ -13,6 +13,7 @@ message modules {
           optional binary debugName (UTF8);
           optional binary version (UTF8);
           optional binary debugID (UTF8);
+          optional binary certSubject (UTF8);
         }
       }
     }
diff --git a/schemas/telemetry/modules/modules.4.schema.json b/schemas/telemetry/modules/modules.4.schema.json
index 971dfbfab..b28d68fac 100644
--- a/schemas/telemetry/modules/modules.4.schema.json
+++ b/schemas/telemetry/modules/modules.4.schema.json
@@ -935,6 +935,12 @@
         "modules": {
           "items": {
             "properties": {
+              "certSubject": {
+                "type": [
+                  "string",
+                  "null"
+                ]
+              },
               "debugID": {
                 "type": [
                   "string",
diff --git a/templates/telemetry/modules/modules.4.parquetmr.txt b/templates/telemetry/modules/modules.4.parquetmr.txt
index 394eb7a70..bd6f26fff 100644
--- a/templates/telemetry/modules/modules.4.parquetmr.txt
+++ b/templates/telemetry/modules/modules.4.parquetmr.txt
@@ -13,6 +13,7 @@ message modules {
           optional binary debugName (UTF8);
           optional binary version (UTF8);
           optional binary debugID (UTF8);
+          optional binary certSubject (UTF8);
         }
       }
     }
diff --git a/templates/telemetry/modules/modules.4.schema.json b/templates/telemetry/modules/modules.4.schema.json
index 2b1c0d037..2c5afbf92 100644
--- a/templates/telemetry/modules/modules.4.schema.json
+++ b/templates/telemetry/modules/modules.4.schema.json
@@ -32,6 +32,9 @@
               },
               "debugID": {
                 "type": [ "string", "null" ]
+              },
+              "certSubject": {
+                "type": [ "string", "null" ]
               }
             }
           }
diff --git a/validation/telemetry/modules.4.windows.pass.json b/validation/telemetry/modules.4.windows.pass.json
index eafd9ab28..cc0f5f167 100644
--- a/validation/telemetry/modules.4.windows.pass.json
+++ b/validation/telemetry/modules.4.windows.pass.json
@@ -21,13 +21,15 @@
         "name": "firefox.exe",
         "debugName": "firefox.pdb",
         "debugID": "3046805AB5E34628BC9B5041DF253A02C",
-        "version": "53.0.0.6228"
+        "version": "53.0.0.6228",
+        "certSubject": "Mozilla Corporation"
       },
       {
         "name": "ntdll.dll",
         "debugName": "wntdll.pdb",
         "debugID": "9D5EBB427B3449C0BA160009A90706251",
-        "version": "10.0.14393.479"
+        "version": "10.0.14393.479",
+        "certSubject": "Microsoft Windows"
       },
       {
         "name": "KERNEL32.DLL",