diff --git a/ivette/Makefile.installation b/ivette/Makefile.installation
index 7a69ff94f9cdf51f8e251481a32859576771b14f..7ca2ee4119213f0bdc8390a078b86801ce9eba15 100644
--- a/ivette/Makefile.installation
+++ b/ivette/Makefile.installation
@@ -28,7 +28,7 @@ ifndef PREFIX
 then
 install::
 	@echo "Warning: not target for Ivette"
-	@echo "  (no INSTALLDIR, nor OPAM_SWITCH_PREFIX)"
+	@echo "  (no PREFIX, nor OPAM_SWITCH_PREFIX)"
 else
 install::
 	@echo "Installing Ivette to ${PREFIX}"