diff --git a/source/include/acoutput.h b/source/include/acoutput.h
index 1d6aacca55..46774ad0fa 100644
--- a/source/include/acoutput.h
+++ b/source/include/acoutput.h
@@ -508,7 +508,7 @@
  *
  * A less-safe version of the macros is provided for optional use if the
  * compiler uses excessive CPU stack (for example, this may happen in the
- * debug case if code optimzation is disabled.)
+ * debug case if code optimization is disabled.)
  */
 
 /* Exit trace helper macro */