ERROR: type modifier is not allowed for type "geometry" in PostGIS 2.1
<p>On Debian Wheezy I had postgresql 9.1 installed and installed the postGIS 1.5 from the standard apt repo. This didn't have the geometry type however so I added the postgresql apt repo and installed postgis 2.1:</p>

<pre><code>sudo apt-get install postgis-2.1
</code></pre>

<p>the last output of which related to postgis was:</p>

<pre><code>Setting up postgresql-9.4-postgis-2.2 (2.2.1+dfsg-2.pgdg70+1)
</code></pre>

<p>All appeared good but when I run the following sql the same error as in postGIS 1.5 results:</p>

<pre><code>ALTER TABLE bolls ADD COLUMN location geometry(POINT,-1);
</code></pre>

<p>Edit:
After instruction from Nick Barnes in comment below I tried <code>ALTER EXTENSION postgis update to "2.1";</code> and got </p>

<pre><code>ERROR:  extension "postgis" does not exist
</code></pre>

<p>If I try <code>CREATE EXTENSION postgis</code> it tells me PostGIS is already installed.</p>