diff --git a/R/utilities-patterns.R b/R/utilities-patterns.R
index b7a97b3a3f..030ad6b742 100644
--- a/R/utilities-patterns.R
+++ b/R/utilities-patterns.R
@@ -36,7 +36,7 @@ fill_alpha <- function(fill, alpha) {
     # key that is trying to draw a single colour. It can be given that colour
     # as a list due to patterns in other keys.
     msg <- paste0(
-      "{.field fill} must be a valid colour or list of ",
+      "{.field fill} must be a vector of colours or list of ",
       "{.cls GridPattern} objects."
     )
     # If single colour list, try applying `alpha()`
diff --git a/tests/testthat/_snaps/patterns.md b/tests/testthat/_snaps/patterns.md
index 9582595d23..5a9374a4d6 100644
--- a/tests/testthat/_snaps/patterns.md
+++ b/tests/testthat/_snaps/patterns.md
@@ -1,8 +1,8 @@
 # fill_alpha works as expected
 
-    fill must be a valid colour or list of <GridPattern> objects.
+    fill must be a vector of colours or list of <GridPattern> objects.
 
 ---
 
-    fill must be a valid colour or list of <GridPattern> objects.
+    fill must be a vector of colours or list of <GridPattern> objects.