diff --git a/regex-capi/include/rure.h b/regex-capi/include/rure.h
index 7b910e7d4..23537db7e 100644
--- a/regex-capi/include/rure.h
+++ b/regex-capi/include/rure.h
@@ -12,7 +12,7 @@ extern "C" {
 /*
  * rure is the type of a compiled regular expression.
  *
- * An rure can be safely used from multiple threads simultaneously.
+ * A rure can be safely used from multiple threads simultaneously.
  */
 typedef struct rure rure;