diff --git a/browser/installer/windows/nsis/shared.nsh b/browser/installer/windows/nsis/shared.nsh
index 6de440e1f71a..b6f81b4385a3 100755
--- a/browser/installer/windows/nsis/shared.nsh
+++ b/browser/installer/windows/nsis/shared.nsh
@@ -430,6 +430,30 @@ FunctionEnd
     WriteRegStr SHCTX "$0\.xhtml" "" "FirefoxHTML"
   ${EndIf}
 
+  ; Only add .oga if it's not present
+  ${CheckIfRegistryKeyExists} "$0" ".oga" $7
+  ${If} $7 == "false"
+    WriteRegStr SHCTX "$0\.oga"  "" "FirefoxHTML"
+  ${EndIf}
+
+  ; Only add .ogg if it's not present
+  ${CheckIfRegistryKeyExists} "$0" ".ogg" $7
+  ${If} $7 == "false"
+    WriteRegStr SHCTX "$0\.ogg"  "" "FirefoxHTML"
+  ${EndIf}
+
+  ; Only add .ogv if it's not present
+  ${CheckIfRegistryKeyExists} "$0" ".ogv" $7
+  ${If} $7 == "false"
+    WriteRegStr SHCTX "$0\.ogv"  "" "FirefoxHTML"
+  ${EndIf}
+
+  ; Only add .pdf if it's not present
+  ${CheckIfRegistryKeyExists} "$0" ".pdf" $7
+  ${If} $7 == "false"
+    WriteRegStr SHCTX "$0\.pdf"  "" "FirefoxHTML"
+  ${EndIf}
+
   ; Only add webm if it's not present
   ${CheckIfRegistryKeyExists} "$0" ".webm" $7
   ${If} $7 == "false"
diff --git a/browser/installer/windows/nsis/uninstaller.nsi b/browser/installer/windows/nsis/uninstaller.nsi
index a9ba76bfeb9f..70bd88f4bf51 100755
--- a/browser/installer/windows/nsis/uninstaller.nsi
+++ b/browser/installer/windows/nsis/uninstaller.nsi
@@ -324,6 +324,10 @@ Section "Uninstall"
     ${un.RegCleanFileHandler}  ".shtml" "FirefoxHTML"
     ${un.RegCleanFileHandler}  ".xht"   "FirefoxHTML"
     ${un.RegCleanFileHandler}  ".xhtml" "FirefoxHTML"
+    ${un.RegCleanFileHandler}  ".oga"  "FirefoxHTML"
+    ${un.RegCleanFileHandler}  ".ogg"  "FirefoxHTML"
+    ${un.RegCleanFileHandler}  ".ogv"  "FirefoxHTML"
+    ${un.RegCleanFileHandler}  ".pdf"  "FirefoxHTML"
     ${un.RegCleanFileHandler}  ".webm"  "FirefoxHTML"
   ${EndIf}