diff --git a/README.md b/README.md
index 458fe67e0ca3ccda3b108f31c4bc6d4b49aec240..3afa23367c487335dc3299fcad6b77ce60e00791 100644
--- a/README.md
+++ b/README.md
@@ -18,6 +18,12 @@ the files you need:
 SESSIONDIR=/home/formacion/COMUNES/IAMZ/data/CIHEAM/sessions/variant_annotation
 ~~~~
 
+And make sure python3 can be found:
+
+~~~~ {.bash}
+alias python3='/home/formacion/COMUNES/IAMZ/soft/python-3.4.2/bin/python3.4'
+~~~~
+
 ### Slicing and dicing of VCF files
 
 VCF files can get very big. Being able to manipulate them and extract
@@ -28,7 +34,7 @@ called variants of chromosome 18, bgzip-ping them on-the-fly, and then
 indexing that file with tabix:
 
 ~~~~ {.bash}
-tabix -h /home/formacion/COMUNES/IAMZ/data/CIHEAM/MULTISAMPLE_VCF/allbt.vcf.gz 18 | bgzip >BT18.vcf.gz
+tabix -h $SESSIONDIR/allbt.vcf.gz 18 | bgzip >BT18.vcf.gz
 tabix -p vcf BT18.vcf.gz
 ~~~~
 
diff --git a/Tutorial.html b/Tutorial.html
index 5c8ec0ed36a75735fb7ec81f4276b1d4afb47a8d..db6d0e05c5a8a8a8612a528e18d8429fd221315f 100644
--- a/Tutorial.html
+++ b/Tutorial.html
@@ -34,9 +34,11 @@ code > span.er { color: #ff0000; font-weight: bold; }
 <span class="kw">cd</span> annotation_session</code></pre>
 <p>Create an Env.Var. to the communal session directory that holds some of the files you need:</p>
 <pre class="sourceCode bash"><code class="sourceCode bash"><span class="ot">SESSIONDIR=</span>/home/formacion/COMUNES/IAMZ/data/CIHEAM/sessions/variant_annotation</code></pre>
+<p>And make sure python3 can be found:</p>
+<pre class="sourceCode bash"><code class="sourceCode bash"><span class="kw">alias</span> python3=<span class="st">&#39;/home/formacion/COMUNES/IAMZ/soft/python-3.4.2/bin/python3.4&#39;</span></code></pre>
 <h3 id="slicing-and-dicing-of-vcf-files">Slicing and dicing of VCF files</h3>
 <p>VCF files can get very big. Being able to manipulate them and extract relevant information is important. In practice, flat text files such as VCF are currently the basis for further analysis - see the Imputation and Population practical sessions. The first task involves selecting all called variants of chromosome 18, bgzip-ping them on-the-fly, and then indexing that file with tabix:</p>
-<pre class="sourceCode bash"><code class="sourceCode bash"><span class="kw">tabix</span> -h /home/formacion/COMUNES/IAMZ/data/CIHEAM/MULTISAMPLE_VCF/allbt.vcf.gz 18 <span class="kw">|</span> <span class="kw">bgzip</span> <span class="kw">&gt;</span>BT18.vcf.gz
+<pre class="sourceCode bash"><code class="sourceCode bash"><span class="kw">tabix</span> -h <span class="ot">$SESSIONDIR</span>/allbt.vcf.gz 18 <span class="kw">|</span> <span class="kw">bgzip</span> <span class="kw">&gt;</span>BT18.vcf.gz
 <span class="kw">tabix</span> -p vcf BT18.vcf.gz</code></pre>
 <p>Have a look at what is inside this file:</p>
 <pre class="sourceCode bash"><code class="sourceCode bash"><span class="kw">gunzip</span> -c BT18.vcf.gz <span class="kw">|</span> <span class="kw">grep</span> -v <span class="st">&#39;^##&#39;</span> <span class="kw">|</span> <span class="kw">more</span></code></pre>
diff --git a/Tutorial.wiki b/Tutorial.wiki
index 1dec2c58f2a5d617ca30c35b7caa17f0fb485428..e66c902129b424f49c85a90414949bbb6e298ed5 100644
--- a/Tutorial.wiki
+++ b/Tutorial.wiki
@@ -13,13 +13,17 @@ Create an Env.Var. to the communal session directory that holds some of the file
 <source lang='bash'>
 SESSIONDIR=/home/formacion/COMUNES/IAMZ/data/CIHEAM/sessions/variant_annotation
 </source>
+And make sure python3 can be found:
+<source lang='bash'>
+alias python3='/home/formacion/COMUNES/IAMZ/soft/python-3.4.2/bin/python3.4'
+</source>
 
 === Slicing and dicing of VCF files ===
 
 VCF files can get very big. Being able to manipulate them and extract relevant information is important. In practice, flat text files such as VCF are currently the basis for further analysis - see the Imputation and Population practical sessions. The first task involves selecting all called variants of chromosome 18, bgzip-ping them on-the-fly, and then indexing that file with tabix:
 
 <source lang='bash'>
-tabix -h /home/formacion/COMUNES/IAMZ/data/CIHEAM/MULTISAMPLE_VCF/allbt.vcf.gz 18 | bgzip >BT18.vcf.gz
+tabix -h $SESSIONDIR/allbt.vcf.gz 18 | bgzip >BT18.vcf.gz
 tabix -p vcf BT18.vcf.gz
 </source>