diff --git a/calibration.html b/calibration.html
index 76e951a..5868b19 100644
--- a/calibration.html
+++ b/calibration.html
@@ -98,7 +98,7 @@
                 {REPLACE "G1 E0.0000 F2700\n" ";unretract6\n"}</pre>
             <h4>Changes made per test to the base slicing profile</h4>
             <p>The information below is mainly for my reference. However, if you wish to duplicate the tests yourself out of interest or perhaps to develop a new test for the site, then the steps must be followed exactly.</p>
-            <p>First layer test: No changes, although it should be noted that a single square is included which is then duplicated and positioned by this site. Non uniform scaling of the souce STL needs to occur to suit certain nozzle/layer combinations.</p>
+            <p>First layer test: No changes, although it should be noted that a single square is included which is then duplicated and positioned by this site. Non uniform scaling of the source STL needs to occur to suit certain nozzle/layer combinations.</p>
             <p>Baseline test: No changes</p>
             <p>Retraction test:</p>
             <ul>