diff --git a/scripts/build-book b/scripts/build-book
index 810608e..4b56c42 100755
--- a/scripts/build-book
+++ b/scripts/build-book
@@ -47,10 +47,22 @@ sub cp-temp($src) {
 
 # Invoke katla on a source file, streaming its output to the temporary directory
 sub katla($src, $ttc-src) {
-    # TODO: Post process them to set themeing correctly
     # Run katla and collect the output
     my $katla = run 'katla', 'markdown', $src, $ttc-src, :out;
     my $output = $katla.out.slurp(:close);
+    # TODO: Post process them to set themeing correctly
+    $output ~~ s:g/'<style>' .* '</style>'//;
+    $output ~~ s:g/'<br />'//;
+    $output ~~ s:g/'<code'/<pre><code/;
+    $output ~~ s:g/'</code>'/<\/code><\/pre>/;
+    $output ~~ s:g/'class="IdrisKeyword"'/class="hljs-keyword"/;
+    $output ~~ s:g/'class="IdrisModule"'/class="hljs-symbol hljs-emphasis"/;
+    $output ~~ s:g/'class="IdrisComment"'/class="hljs-comment"/;
+    $output ~~ s:g/'class="IdrisFunction"'/class="hljs-symbol"/;
+    $output ~~ s:g/'class="IdrisBound"'/class="hljs-name"/;
+    $output ~~ s:g/'class="IdrisData"'/class="hljs-title"/;
+    $output ~~ s:g/'class="IdrisType"'/class="hljs-type"/;
+    $output ~~ s:g/'class="IdrisNamespace"'/class="hljs-symbol hljs-emphasis"/;
     # Spurt the output to the temporary directory
     my $output-path = $tempdir.add: $src;
     if !$output-path.parent.d {