diff --git a/security/opensc/Makefile b/security/opensc/Makefile
index 6b15000f9bfc..cec9dfb684b2 100644
--- a/security/opensc/Makefile
+++ b/security/opensc/Makefile
@@ -11,7 +11,7 @@ COMMENT=	Libraries and utilities to access smart cards
 
 LICENSE=	LGPL21
 
-USES=		autoreconf compiler gmake libtool pkgconfig ssl
+USES=		autoreconf compiler:c11 gmake libtool pkgconfig ssl
 
 OPTIONS_SINGLE=	BACKEND
 OPTIONS_SINGLE_BACKEND=PCSC OPENCT CTAPI
@@ -70,12 +70,4 @@ CONFIGURE_ENV+=	XSLTPROC="${FALSE}"
 CONFIGURE_ARGS+=--without-xsl-stylesheetsdir
 .endif
 
-.include <bsd.port.pre.mk>
-
-.if ${CHOSEN_COMPILER_TYPE} == gcc
-post-patch:
-	${REINPLACE_CMD} -e '/-Wno-unused-but-set-variable/d' \
-		${WRKSRC}/src/tools/Makefile.am
-.endif
-
-.include <bsd.port.post.mk>
+.include <bsd.port.mk>
diff --git a/security/opensc/files/patch-src_tests_p11test_p11test.c b/security/opensc/files/patch-src_tests_p11test_p11test.c
new file mode 100644
index 000000000000..022b84ef5929
--- /dev/null
+++ b/security/opensc/files/patch-src_tests_p11test_p11test.c
@@ -0,0 +1,11 @@
+--- src/tests/p11test/p11test.c.orig	2019-10-30 14:56:38 UTC
++++ src/tests/p11test/p11test.c
+@@ -49,7 +49,7 @@ void display_usage() {
+ }
+ 
+ int main(int argc, char** argv) {
+-	char command;
++	signed char command;
+ 	const struct CMUnitTest readonly_tests_without_initialization[] = {
+ 		/* Test card events on slot */
+ 		cmocka_unit_test_setup_teardown(wait_test,