diff --git a/relational-data.Rmd b/relational-data.Rmd
index 6010c32..a90bcc7 100644
--- a/relational-data.Rmd
+++ b/relational-data.Rmd
@@ -452,7 +452,7 @@ flights %>%
     patterns?
 
 1.  What does `anti_join(flights, airports, by = c("dest" = "faa"))` tell you?
-    What does `anti_join(airports, flights, by = c("dest" = "faa"))` tell you?
+    What does `anti_join(airports, flights, by = c("faa" = "dest"))` tell you?
 
 ## Join problems