diff --git a/mk/target.mk b/mk/target.mk
index 86b85cb5617ceec0a50af174c639bfc75948607e..cbd0308eed42fdb042b63cdda7f7eca3da619c66 100644
--- a/mk/target.mk
+++ b/mk/target.mk
@@ -876,13 +876,17 @@ SGML_TEXT = $(SGML_DOC).txt
 
 else # no SGML_DOC
 
+ifeq "$(VSGML_SRCS)" ""
 VSGML_SRCS = $(wildcard *.vsgml)
+endif
 
+ifeq "$(SGML_SRCS)" ""
 ifneq "$(VSGML_SRCS)" ""
 SGML_SRCS  = $(addsuffix .sgml, $(basename $(VSGML_SRCS)))
 else
 SGML_SRCS  = $(wildcard *.sgml)
 endif
+endif
 
 SGML_DVI  = $(addsuffix  .dvi, $(basename $(SGML_SRCS)))
 SGML_PS   = $(addsuffix   .ps, $(basename $(SGML_SRCS)))