diff --git a/src/99-appendices/08-coordinate-systems.md b/src/99-appendices/08-coordinate-systems.md
index 7decbb8eee..8bbd7ca824 100644
--- a/src/99-appendices/08-coordinate-systems.md
+++ b/src/99-appendices/08-coordinate-systems.md
@@ -1,4 +1,4 @@
-# Appendix VIII: Coordinate Systems
+# Appendix VIII: Coordinate systems
 
 To interpret a coordinate (x, y, z), it is required that you know relative to
 which origin the coordinates are expressed, you have to know the interpretation