diff --git a/src/usage.txt b/src/usage.txt
index b23e1ad..1d4c6c1 100644
--- a/src/usage.txt
+++ b/src/usage.txt
@@ -1,7 +1,7 @@
-"o" to open a new image
-"r" to rotate
-"i" to invert colors
-"f" to switch filter
-"b" to toggle the bar
-"s" to save the image
-"q" to quit
+'o' to open a new image
+'r' to rotate
+'i' to invert colors
+'f' to switch filter
+'b' to toggle the bar
+'s' to save the image
+'q' to quit