diff --git a/biology/seaview/Makefile b/biology/seaview/Makefile
index 922134459401..3508d87dfddc 100644
--- a/biology/seaview/Makefile
+++ b/biology/seaview/Makefile
@@ -12,9 +12,6 @@ COMMENT=	Multiple DNA/protein sequence alignment editor
 
 LICENSE=	GPLv3
 
-BROKEN_FreeBSD_13=	ld: error: duplicate symbol: progname
-BROKEN_FreeBSD_14=	ld: error: duplicate symbol: progname
-
 LIB_DEPENDS=	libfltk.so:x11-toolkits/fltk \
 		libfontconfig.so:x11-fonts/fontconfig \
 		libpng.so:graphics/png
@@ -40,6 +37,10 @@ post-patch:
 	${REINPLACE_CMD} -e \
 		's|^\(CC\) |#\1 | ; s|-ldl || ; \
 		s|^\(CXX\) |#\1 |' ${WRKSRC}/Makefile
+	${REINPLACE_CMD} -E \
+		'/firstplotblock|javarun|\*progname/s,^,extern ,' \
+		${WRKSRC}/csrc/phylip.h ${WRKSRC}/csrc/protpars.c
+	${ECHO_CMD} 'boolean javarun;' >> ${WRKSRC}/csrc/phylip.c
 
 do-install:
 	(cd ${WRKSRC} && ${INSTALL_PROGRAM} seaview \
diff --git a/biology/seaview/files/patch-csrc_dnapars.c b/biology/seaview/files/patch-csrc_dnapars.c
new file mode 100644
index 000000000000..ecf81d66f4ae
--- /dev/null
+++ b/biology/seaview/files/patch-csrc_dnapars.c
@@ -0,0 +1,70 @@
+--- csrc/dnapars.c.orig	2019-11-29 14:00:33 UTC
++++ csrc/dnapars.c
+@@ -77,41 +77,44 @@ void   load_tree(long treei);
+ /* function prototypes */
+ 
+ 
+-Char infilename[FNMLNGTH], outfilename[FNMLNGTH], intreename[FNMLNGTH], *outtreename,
++extern Char infilename[FNMLNGTH], outfilename[FNMLNGTH], intreename[FNMLNGTH], *outtreename,
+      weightfilename[FNMLNGTH];
+ char basechar[32]="ACMGRSVTWYHKDBNO???????????????";
+-node *root;
+-long chars, col, msets, ith, njumble, jumb, maxtrees;
++extern node *root;
++extern long chars, col, msets, ith, njumble, jumb;
++long maxtrees;
+ /*   chars = number of sites in actual sequences */
+-long inseed, inseed0;
+-double threshold;
+-boolean jumble, usertree, thresh, weights, thorough, rearrfirst,
+-          trout, progress, stepbox, ancseq, mulsets, justwts, firstset, mulf,
+-          multf;
++extern long inseed, inseed0;
++extern double threshold;
++extern boolean jumble, usertree, thresh, weights,
++          trout, progress, stepbox, ancseq, mulsets, justwts, firstset;
++boolean thorough, rearrfirst, mulf, multf;
+ steptr oldweight;
+-longer seed;
+-pointarray treenode;            /* pointers to all nodes in tree */
+-long *enterorder;
++extern longer seed;
++extern pointarray treenode;            /* pointers to all nodes in tree */
++extern long *enterorder;
+ long *zeros;
+ 
+ /* local variables for Pascal maketree, propagated globally for C version: */
+ 
+-long minwhich;
++extern long minwhich;
+ static double like, minsteps, bestyet, bestlike, bstlike2;
+-boolean lastrearr, recompute;
+-double nsteps[maxuser];
+-long **fsteps;
+-node *there, *oldnufork;
+-long *place;
+-bestelm *bestrees;
+-long *threshwt;
++extern boolean lastrearr, recompute;
++extern double nsteps[maxuser];
++extern long **fsteps;
++extern node *there;
++node *oldnufork;
++extern long *place;
++extern bestelm *bestrees;
++extern long *threshwt;
+ baseptr nothing;
+-gbases *garbage;
+-node *temp, *temp1, *temp2, *tempsum, *temprm, *tempadd, *tempf, *tmp, *tmp1,
++extern gbases *garbage;
++extern node *temp, *temp1;
++node *temp2, *tempsum, *temprm, *tempadd, *tempf, *tmp, *tmp1,
+        *tmp2, *tmp3, *tmprm, *tmpadd;
+-boolean *names;
++extern boolean *names;
+ node *grbg;
+-char *progname;
++extern char *progname;
+ 
+ 
+ static void getoptions(int arg_maxtrees, dnapars_S_option s_option)