diff -up bibutils_6.5/bin/Makefile~ bibutils_6.5/bin/Makefile
--- bibutils_6.5/bin/Makefile.dynamic~	2018-06-29 17:42:26.485528548 +0900
+++ bibutils_6.5/bin/Makefile.dynamic	2018-06-29 18:02:55.305754734 +0900
@@ -5,7 +5,7 @@
 #
 
 CFLAGS     = -I ../lib $(CFLAGSIN)
-LDFLAGS    = -L ../lib
+LDFLAGS    = -L ../lib $(LDFLAGSIN)
 LDLIBS     = -lbibutils
 
 TOMODS     = bibprog.o tomods.o args.o
diff -up bibutils_6.5/lib/Makefile~ bibutils_6.5/lib/Makefile
--- bibutils_6.5/lib/Makefile.dynamic~	2018-06-29 17:42:26.484528544 +0900
+++ bibutils_6.5/lib/Makefile.dynamic	2018-06-29 18:01:03.557281315 +0900
@@ -1,4 +1,5 @@
 CFLAGS    = $(CFLAGSIN)
+LDFLAGS   = $(LDFLAGSIN)
 LIBTARGET = $(LIBTARGETIN)
 
 SIMPLE_OBJS   = charsets.o \
@@ -75,12 +76,12 @@ all: $(LIBTARGET)
 	$(CC) $(CFLAGS) -c -o $@ $<
 
 libbibutils.so: $(BIBCORE_OBJS) $(BIBUTILS_OBJS)
-	$(CC) -shared -Wl,-soname,$(SONAME) -o $(SOFULL) $^
+	$(CC) $(LDFLAGS) -shared -Wl,-soname,$(SONAME) -o $(SOFULL) $^
 	ln -sf $(SOFULL) $(SONAME)
 	ln -sf $(SOFULL) libbibutils.so
 
 bibutils.dll: $(BIBCORE_OBJS) $(BIBUTILS_OBJS)
-	$(CC) -shared -Wl,-soname,$(SONAME) -o $@ $^
+	$(CC) $(LDFLAGS) -shared -Wl,-soname,$(SONAME) -o $@ $^
 	cp $@ ../bin
 	cp $@ ../test
 
diff -up bibutils_6.5/test/Makefile~ bibutils_6.5/test/Makefile
--- bibutils_6.5/test/Makefile.dynamic~	2018-06-29 17:42:26.486528552 +0900
+++ bibutils_6.5/test/Makefile.dynamic	2018-06-29 18:01:21.021355301 +0900
@@ -3,7 +3,7 @@
 #
 
 CFLAGS   = -I ../lib $(CFLAGSIN)
-LDFLAGS  = -L ../lib
+LDFLAGS  = -L ../lib $(LDFLAGSIN)
 LDLIBS   = -lbibutils
 
 PROGS    = doi_test \