diff --git a/src/pl/plperl/GNUmakefile b/src/pl/plperl/GNUmakefile
index 79a8d5d3fadbc70169384c83fe55c4cef3a66e8e..aa44827bfa76734ba5ed9f985dd170f30fa51f95 100644
--- a/src/pl/plperl/GNUmakefile
+++ b/src/pl/plperl/GNUmakefile
@@ -60,17 +60,21 @@ include $(top_srcdir)/src/Makefile.shlib
 plperl.o: perlchunks.h plperl_opmask.h
 
 plperl_opmask.h: plperl_opmask.pl
+	@if [ x"$(perl_privlibexp)" = x"" ]; then echo "configure switch --with-perl was not specified."; exit 1; fi
 	$(PERL) $< $@
 
 perlchunks.h: $(PERLCHUNKS)
+	@if [ x"$(perl_privlibexp)" = x"" ]; then echo "configure switch --with-perl was not specified."; exit 1; fi
 	$(PERL) $(srcdir)/text2macro.pl --strip='^(\#.*|\s*)$$' $^ > $@
 
 all: all-lib
 
 SPI.c: SPI.xs
+	@if [ x"$(perl_privlibexp)" = x"" ]; then echo "configure switch --with-perl was not specified."; exit 1; fi
 	$(PERL) $(perl_privlibexp)/ExtUtils/xsubpp -typemap $(perl_privlibexp)/ExtUtils/typemap $< >$@
 
 Util.c: Util.xs
+	@if [ x"$(perl_privlibexp)" = x"" ]; then echo "configure switch --with-perl was not specified."; exit 1; fi
 	$(PERL) $(perl_privlibexp)/ExtUtils/xsubpp -typemap $(perl_privlibexp)/ExtUtils/typemap $< >$@