diff --git a/drivers/ramdisk/Makefile b/drivers/ramdisk/Makefile
index 456444777..160458bdd 100644
--- a/drivers/ramdisk/Makefile
+++ b/drivers/ramdisk/Makefile
@@ -97,10 +97,12 @@ ${etc}: ${NETBSDSRCDIR}/etc/${etc}
 
 # LSC Force the regeneration of the proto file as it seems sometimes 
 # they are not copied over as needed.
+# LSC The test is needed; otherwise install complains about src and dst
+# being the same, during in-tree builds
 # LSC ramdisk rc file != /etc/rc && mtab not empty!
 .for file in ${EXTRA} ${PROTO} ${PROTO_FILES}
 ${file}: ${NETBSDSRCDIR}/drivers/ramdisk/${file} .PHONY
-	${INSTALL} $> $@
+	[ -e $@ ] || ${INSTALL} $> $@
 .endfor
 
 # Generate dependencies rules for dynamic libraries, if needed