diff --git a/bin/clean.sh b/bin/clean.sh
index b282f332c..522479edb 100755
--- a/bin/clean.sh
+++ b/bin/clean.sh
@@ -2,4 +2,4 @@
 
 # Remove any output files
 
-find . -regex "^./editions/[a-z\.-]*/output/.*" -delete
+find . -regex "^./editions/[a-z0-9\.-]*/output/.*" -delete