diff --git a/docs/framework_downloader.rst b/docs/framework_downloader.rst
index fcca8619f..45d75e459 100644
--- a/docs/framework_downloader.rst
+++ b/docs/framework_downloader.rst
@@ -20,6 +20,9 @@ Keys common to both repo and cog info.json (case sensitive)
 
 - ``install_msg`` (string) - The message that gets displayed when a cog 
   is installed or a repo is added
+  
+  .. tip:: You can use the ``[p]`` key in your string to use the prefix
+      used for installing.
 
 - ``short`` (string) - A short description of the cog or repo. For cogs, this info 
   is displayed when a user executes ``!cog list``
diff --git a/redbot/cogs/downloader/downloader.py b/redbot/cogs/downloader/downloader.py
index 87b69be4c..f9d3090a6 100644
--- a/redbot/cogs/downloader/downloader.py
+++ b/redbot/cogs/downloader/downloader.py
@@ -234,7 +234,7 @@ class Downloader:
         else:
             await ctx.send(_("Repo `{}` successfully added.").format(name))
             if repo.install_msg is not None:
-                await ctx.send(repo.install_msg)
+                await ctx.send(repo.install_msg.replace("[p]", ctx.prefix))
 
     @repo.command(name="delete")
     async def _repo_del(self, ctx, repo_name: Repo):
@@ -319,7 +319,7 @@ class Downloader:
 
         await ctx.send(_("`{}` cog successfully installed.").format(cog_name))
         if cog.install_msg is not None:
-            await ctx.send(cog.install_msg)
+            await ctx.send(cog.install_msg.replace("[p]", ctx.prefix))
 
     @cog.command(name="uninstall")
     async def _cog_uninstall(self, ctx, cog_name: InstalledCog):