diff --git a/devel/rubygem-concurrent-ruby-ext/Makefile b/devel/rubygem-concurrent-ruby-ext/Makefile
index 90cda04607c3..e2f16ba8293f 100644
--- a/devel/rubygem-concurrent-ruby-ext/Makefile
+++ b/devel/rubygem-concurrent-ruby-ext/Makefile
@@ -1,23 +1,17 @@
 PORTNAME=	concurrent-ruby-ext
 PORTVERSION=	1.2.2
 CATEGORIES=	devel rubygems
 MASTER_SITES=	RG
 
 MAINTAINER=	sunpoet@FreeBSD.org
 COMMENT=	C extensions to optimize the concurrent-ruby
 WWW=		https://github.com/ruby-concurrency/concurrent-ruby
 
 LICENSE=	MIT
 LICENSE_FILE=	${WRKSRC}/LICENSE.txt
 
 RUN_DEPENDS=	rubygem-concurrent-ruby>=${PORTVERSION}<${PORTVERSION}_99:devel/rubygem-concurrent-ruby
 
 USES=		gem
 
-.include <bsd.port.options.mk>
-
-.if ${OPSYS} == FreeBSD && ( ${OSVERSION} >= 1400079 || ( ${OSVERSION} >= 1302505 && ${OSVERSION} < 1400000 ))
-CONFIGURE_ARGS+=	--with-cflags="-Wno-error=int-conversion"
-.endif
-
 .include <bsd.port.mk>
diff --git a/devel/rubygem-concurrent-ruby-ext/files/patch-clang15 b/devel/rubygem-concurrent-ruby-ext/files/patch-clang15
new file mode 100644
index 000000000000..6dc21f68ba35
--- /dev/null
+++ b/devel/rubygem-concurrent-ruby-ext/files/patch-clang15
@@ -0,0 +1,11 @@
+--- ext/concurrent-ruby-ext/atomic_reference.c.orig	2023-06-13 15:43:55 UTC
++++ ext/concurrent-ruby-ext/atomic_reference.c
+@@ -105,7 +105,7 @@ VALUE ir_compare_and_set(volatile VALUE self, VALUE ex
+     return Qtrue;
+   }
+ #else
+-  if (__sync_bool_compare_and_swap(&DATA_PTR(self), expect_value, new_value)) {
++  if (__sync_bool_compare_and_swap(&DATA_PTR(self), (void *) expect_value, (void *) new_value)) {
+     return Qtrue;
+   }
+ #endif