diff --git a/ChangeLog b/ChangeLog
index 2134c3c7da1b56f06756566a2822ff4d16803047..ddce6334ec0fb247c0abe397f4e5b558e0d1a915 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,6 +3,7 @@ version 0.9.6 -- unreleased
 	 . fix bug in cstream definition, thanks Jamie McClelland
 	 . Allow the entire backup run to be halted by an action, thanks to
 	   Matthew Palmer (Closes: #455836)
+	 . Fixed tr construct reporting a warning (Closes: #452669)
     handler changes
 	dup:
 	 . General cleanup
diff --git a/src/backupninja.in b/src/backupninja.in
index 75b892af5f4a7b19d2ec23a3cb859d449f4433f4..47630f282dc01572830e9b79d0ee5ba2159442b5 100755
--- a/src/backupninja.in
+++ b/src/backupninja.in
@@ -180,7 +180,7 @@ function check_perms() {
 
 # simple lowercase function
 function tolower() {
-	echo "$1" | tr [:upper:] [:lower:]
+	echo "$1" | tr '[:upper:]' '[:lower:]'
 }
 
 # simple to integer function