diff --git a/README.md b/README.md
index 54a6a93..e957216 100644
--- a/README.md
+++ b/README.md
@@ -29,9 +29,9 @@ use Text::FriBidi::Lines;
 use Test;
 plan 1;
 
-constant $LRO = 0x202D.chr;
-constant $RLO = 0x202E.chr;
-constant $PDF = 0x202C.chr;
+constant $LRO = "\c[LEFT-TO-RIGHT OVERRIDE]";
+constant $RLO = "\c[RIGHT-TO-LEFT OVERRIDE]";
+constant $PDF = "\c[POP DIRECTIONAL FORMATTING]";
 
 @lines = "Left", "{$RLO}Right{$PDF}", "{$LRO}left{$PDF}";
 my Text::FriBidi::Lines $para .= new: :@lines;
diff --git a/t/bidi-lines.t b/t/bidi-lines.t
index f74e3d6..46a8de4 100644
--- a/t/bidi-lines.t
+++ b/t/bidi-lines.t
@@ -3,9 +3,9 @@ plan 4;
 
 use Text::FriBidi::Lines;
 
-constant $LRO = 0x202D.chr;
-constant $RLO = 0x202E.chr;
-constant $PDF = 0x202C.chr;
+constant $LRO = "\c[LEFT-TO-RIGHT OVERRIDE]";
+constant $RLO = "\c[RIGHT-TO-LEFT OVERRIDE]";
+constant $PDF = "\c[POP DIRECTIONAL FORMATTING]";
 
 my @lines = "Left", "Right", "left";
 my Text::FriBidi::Lines $bidi .= new: :@lines;