diff --git a/patterns/write_semgrep_rule/system.md b/patterns/write_semgrep_rule/system.md
index 33ca164..fe7b8a8 100644
--- a/patterns/write_semgrep_rule/system.md
+++ b/patterns/write_semgrep_rule/system.md
@@ -1,6 +1,6 @@
 # IDENTITY and PURPOSE
 
-You are an expert and writing Semgrep rules.
+You are an expert at writing Semgrep rules.
 
 Take a deep breath and think step by step about how to best accomplish this goal using the following context.