diff --git a/toolkit/components/places/PlacesUtils.jsm b/toolkit/components/places/PlacesUtils.jsm
index 7ba799b63937..5238103032dd 100644
--- a/toolkit/components/places/PlacesUtils.jsm
+++ b/toolkit/components/places/PlacesUtils.jsm
@@ -880,6 +880,8 @@ this.PlacesUtils = {
    * Set the POST data associated with a bookmark, if any.
    * Used by POST keywords.
    *   @param aBookmarkId
+   *
+   * @deprecated Use PlacesUtils.keywords.insert() API instead.
    */
   setPostDataForBookmark(aBookmarkId, aPostData) {
     if (!aPostData)
@@ -923,6 +925,8 @@ this.PlacesUtils = {
    * Get the POST data associated with a bookmark, if any.
    * @param aBookmarkId
    * @returns string of POST data if set for aBookmarkId. null otherwise.
+   *
+   * @deprecated Use PlacesUtils.keywords.fetch() API instead.
    */
   getPostDataForBookmark(aBookmarkId) {
     let stmt = PlacesUtils.history.DBConnection.createStatement(
diff --git a/toolkit/components/places/nsINavBookmarksService.idl b/toolkit/components/places/nsINavBookmarksService.idl
index 13d803d27569..c11bc1d8e82e 100644
--- a/toolkit/components/places/nsINavBookmarksService.idl
+++ b/toolkit/components/places/nsINavBookmarksService.idl
@@ -533,18 +533,24 @@ interface nsINavBookmarksService : nsISupports
    *
    * Use an empty keyword to clear the keyword associated with the URI.
    * In both of these cases, succeeds but does nothing if the URL/keyword is not found.
+   *
+   * @deprecated Use PlacesUtils.keywords.insert() API instead.
    */
   void setKeywordForBookmark(in long long aItemId, in AString aKeyword);
 
   /**
    * Retrieves the keyword for the given bookmark. Will be void string
    * (null in JS) if no such keyword is found.
+   *
+   * @deprecated Use PlacesUtils.keywords.fetch() API instead.
    */
   AString getKeywordForBookmark(in long long aItemId);
 
   /**
    * Returns the URI associated with the given keyword. Empty if no such
    * keyword is found.
+   *
+   * @deprecated Use PlacesUtils.keywords.fetch() API instead.
    */
   nsIURI getURIForKeyword(in AString keyword);
 
diff --git a/toolkit/components/places/nsNavBookmarks.cpp b/toolkit/components/places/nsNavBookmarks.cpp
index 452fa27b994b..9e15253434d7 100644
--- a/toolkit/components/places/nsNavBookmarks.cpp
+++ b/toolkit/components/places/nsNavBookmarks.cpp
@@ -2445,6 +2445,8 @@ nsNavBookmarks::GetURIForKeyword(const nsAString& aUserCasedKeyword,
   NS_ENSURE_TRUE(!aUserCasedKeyword.IsEmpty(), NS_ERROR_INVALID_ARG);
   *aURI = nullptr;
 
+  PLACES_WARN_DEPRECATED();
+
   // Shortcuts are always lowercased internally.
   nsAutoString keyword(aUserCasedKeyword);
   ToLowerCase(keyword);