diff --git a/share/mk/bsd.nls.mk b/share/mk/bsd.nls.mk
index c578361fdd53..d160a2bcf2d4 100644
--- a/share/mk/bsd.nls.mk
+++ b/share/mk/bsd.nls.mk
@@ -73,6 +73,9 @@ SYMLINKS+= ${NLSSYMLINKS}
 .for file in ${NLS}
 NLSNAME_${file:T}= ${file:T:R}/${NLSNAME}.cat
 .if defined(NLSLINKS_${file:R}) && !empty(NLSLINKS_${file:R})
+.if !empty(NLSLINKS_${file:R}:M${file:R})
+.error NLSLINKS_${file:R} contains itself: ${file:R}
+.endif
 NLSLINKS+=	${file:R}
 .endif
 .for dst in ${NLSLINKS_${file:R}}