diff --git a/meta/classes/testimage.bbclass b/meta/classes/testimage.bbclass
index 8ffaeab284..34173ce68d 100644
--- a/meta/classes/testimage.bbclass
+++ b/meta/classes/testimage.bbclass
@@ -240,7 +240,7 @@ def testimage_main(d):
         with open(tdname, "r") as f:
             td = json.load(f)
     except FileNotFoundError as err:
-        bb.fatal('File %s not found (%s).\nHave you built the image with INHERIT += "testimage" in the conf/local.conf?' % (tdname, err))
+        bb.fatal('File %s not found (%s).\nHave you built the image with IMAGE_CLASSES += "testimage" in the conf/local.conf?' % (tdname, err))
 
     # Some variables need to be updates (mostly paths) with the
     # ones of the current environment because some tests require them.