diff --git a/OPTIMISATION.txt b/OPTIMISATION.txt
index 52516af..f7a8f2a 100644
--- a/OPTIMISATION.txt
+++ b/OPTIMISATION.txt
@@ -31,7 +31,7 @@ When to use what:
 
 Please note, that these recomendations may become out of date if more implementations
 are added in the future; use `./configure --help` to obtain all avaiable options.
-When in doubth, benchmark.
+When in doubt, benchmark.
 
 
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