diff --git a/devel/libdap/Makefile b/devel/libdap/Makefile
index 29e53456c438..243025ce23bb 100644
--- a/devel/libdap/Makefile
+++ b/devel/libdap/Makefile
@@ -1,27 +1,29 @@
 PORTNAME=	libdap
-PORTVERSION=	3.20.11
+DISTVERSION=	3.21.0-27
 CATEGORIES=	devel
 MASTER_SITES=	https://www.opendap.org/pub/source/ \
 		LOCAL/sunpoet
 
 MAINTAINER=	sunpoet@FreeBSD.org
 COMMENT=	SDK which contains an implementation of DAP 2.0 and 4.0
-WWW=		https://www.opendap.org/software/libdap
+WWW=		https://www.opendap.org/software/libdap \
+		https://github.com/OPENDAP/libdap4
 
 LICENSE=	LGPL21
 LICENSE_FILE=	${WRKSRC}/COPYING
 
 LIB_DEPENDS=	libcurl.so:ftp/curl \
 		libuuid.so:misc/e2fsprogs-libuuid
 
 USES=		bison:wrapper charsetfix gmake gnome libtool localbase pathfix ssl
 USE_GNOME=	libxml2
 
 CONFIGURE_ARGS=	ac_cv_lib_crypto_OpenSSL_add_all_algorithms=yes \
 		ac_cv_type_max_align_t=yes
 GNU_CONFIGURE=	yes
 GNU_CONFIGURE_MANPREFIX=${PREFIX}/share
 INSTALL_TARGET=	install-strip
 USE_LDCONFIG=	yes
+WRKSRC=		${WRKDIR}/libdap-${PORTVERSION:R}
 
 .include <bsd.port.mk>
diff --git a/devel/libdap/distinfo b/devel/libdap/distinfo
index 8093bb4f6ce3..6b1ce02b8419 100644
--- a/devel/libdap/distinfo
+++ b/devel/libdap/distinfo
@@ -1,3 +1,3 @@
-TIMESTAMP = 1658506555
-SHA256 (libdap-3.20.11.tar.gz) = 850debf6ee6991350bf31051308093bee35ddd2121e4002be7e130a319de1415
-SIZE (libdap-3.20.11.tar.gz) = 2839026
+TIMESTAMP = 1709390364
+SHA256 (libdap-3.21.0-27.tar.gz) = b5b8229d3aa97fea9bba4a0b11b1ee1c6446bd5f7ad2cff591f86064f465eacf
+SIZE (libdap-3.21.0-27.tar.gz) = 2854614
diff --git a/devel/libdap/files/patch-configure b/devel/libdap/files/patch-configure
index 40d30d4bd013..aa5b17656c44 100644
--- a/devel/libdap/files/patch-configure
+++ b/devel/libdap/files/patch-configure
@@ -1,31 +1,33 @@
---- configure.orig	2022-07-01 21:03:16 UTC
+--- configure.orig	2024-01-04 16:04:42 UTC
 +++ configure
-@@ -30287,28 +30287,6 @@ fi
+@@ -31688,30 +31688,6 @@ fi
  
  
  
--if test -f /etc/redhat-release && grep -q '8\.' /etc/redhat-release; then :
+-if test -f /etc/redhat-release && grep -q '8\.' /etc/redhat-release
+-then :
 -
--        { $as_echo "$as_me:${as_lineno-$LINENO}: Found a RHEL 8 or equivalent system..." >&5
--$as_echo "$as_me: Found a RHEL 8 or equivalent system..." >&6;}
--        if grep -q -v tirpc <<< $CPPFLAGS || grep -q -v tirpc <<< $LDFLAGS; then :
+-        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Found a RHEL 8 or equivalent system..." >&5
+-printf "%s\n" "$as_me: Found a RHEL 8 or equivalent system..." >&6;}
+-        if grep -q -v tirpc <<< $CPPFLAGS || grep -q -v tirpc <<< $LDFLAGS
+-then :
 -
 -            as_fn_error $? "Libdap4 on Redhat Linux 8 requires the tirpc library be included on CPPFLAGS and LDFLAGS" "$LINENO" 5
 -
--else
--  { $as_echo "$as_me:${as_lineno-$LINENO}: and CPPFLAGS and LDFLAGS are set" >&5
--$as_echo "$as_me: and CPPFLAGS and LDFLAGS are set" >&6;}
+-else $as_nop
+-  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: and CPPFLAGS and LDFLAGS are set" >&5
+-printf "%s\n" "$as_me: and CPPFLAGS and LDFLAGS are set" >&6;}
 -
 -fi
 -
--else
+-else $as_nop
 -
--        { $as_echo "$as_me:${as_lineno-$LINENO}: Not a RHEL 8 or equivalent system" >&5
--$as_echo "$as_me: Not a RHEL 8 or equivalent system" >&6;}
+-        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Not a RHEL 8 or equivalent system" >&5
+-printf "%s\n" "$as_me: Not a RHEL 8 or equivalent system" >&6;}
 -
 -fi
 -
 -
- { $as_echo "$as_me:${as_lineno-$LINENO}: checking for pthread_kill in -lpthread" >&5
- $as_echo_n "checking for pthread_kill in -lpthread... " >&6; }
- if ${ac_cv_lib_pthread_pthread_kill+:} false; then :
+ { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for pthread_kill in -lpthread" >&5
+ printf %s "checking for pthread_kill in -lpthread... " >&6; }
+ if test ${ac_cv_lib_pthread_pthread_kill+y}
diff --git a/devel/libdap/pkg-descr b/devel/libdap/pkg-descr
index 0e03f0d206b6..f04deedf850e 100644
--- a/devel/libdap/pkg-descr
+++ b/devel/libdap/pkg-descr
@@ -1,5 +1,3 @@
 libdap is A C++ SDK which contains an implementation of DAP 2.0 and 3.1,
 Client- and Server-side support classes and a prototype implementation
 of the AIS.
-
-See also: https://github.com/OPENDAP/libdap4
diff --git a/devel/libdap/pkg-plist b/devel/libdap/pkg-plist
index 249fceeda31d..fad22a51b361 100644
--- a/devel/libdap/pkg-plist
+++ b/devel/libdap/pkg-plist
@@ -1,160 +1,160 @@
 bin/dap-config
 bin/dap-config-pkgconfig
 bin/getdap
 bin/getdap4
 include/libdap/AlarmHandler.h
 include/libdap/Ancillary.h
 include/libdap/Array.h
 include/libdap/AttrTable.h
 include/libdap/BaseType.h
 include/libdap/BaseTypeFactory.h
 include/libdap/Byte.h
 include/libdap/Clause.h
 include/libdap/Connect.h
 include/libdap/ConstraintEvaluator.h
 include/libdap/Constructor.h
 include/libdap/D4AsyncUtil.h
 include/libdap/D4AttributeType.h
 include/libdap/D4Attributes.h
 include/libdap/D4BaseTypeFactory.h
 include/libdap/D4Connect.h
 include/libdap/D4ConstraintEvaluator.h
 include/libdap/D4Dimensions.h
 include/libdap/D4Enum.h
 include/libdap/D4EnumDefs.h
 include/libdap/D4FilterClause.h
 include/libdap/D4Function.h
 include/libdap/D4FunctionEvaluator.h
 include/libdap/D4Group.h
 include/libdap/D4Maps.h
 include/libdap/D4Opaque.h
 include/libdap/D4ParserSax2.h
 include/libdap/D4RValue.h
 include/libdap/D4Sequence.h
 include/libdap/D4StreamMarshaller.h
 include/libdap/D4StreamUnMarshaller.h
 include/libdap/DAS.h
 include/libdap/DDS.h
 include/libdap/DDXExceptions.h
 include/libdap/DDXParserSAX2.h
 include/libdap/DMR.h
 include/libdap/DODSFilter.h
 include/libdap/DapIndent.h
 include/libdap/DapObj.h
 include/libdap/DapXmlNamespaces.h
 include/libdap/DataDDS.h
 include/libdap/EncodingType.h
 include/libdap/Error.h
 include/libdap/EventHandler.h
 include/libdap/Float32.h
 include/libdap/Float64.h
 include/libdap/GNURegex.h
 include/libdap/GetOpt.h
 include/libdap/Grid.h
 include/libdap/HTTPCache.h
 include/libdap/HTTPCacheDisconnectedMode.h
 include/libdap/HTTPCacheInterruptHandler.h
 include/libdap/HTTPCacheMacros.h
 include/libdap/HTTPCacheResponse.h
 include/libdap/HTTPCacheTable.h
 include/libdap/HTTPConnect.h
 include/libdap/HTTPResponse.h
 include/libdap/Int16.h
 include/libdap/Int32.h
 include/libdap/Int64.h
 include/libdap/Int8.h
 include/libdap/InternalErr.h
 include/libdap/Keywords2.h
 include/libdap/Marshaller.h
 include/libdap/MarshallerThread.h
 include/libdap/ObjectType.h
 include/libdap/PipeResponse.h
 include/libdap/RCReader.h
 include/libdap/RValue.h
 include/libdap/Resource.h
 include/libdap/Response.h
 include/libdap/ResponseTooBigErr.h
 include/libdap/Sequence.h
 include/libdap/ServerFunction.h
 include/libdap/ServerFunctionsList.h
 include/libdap/SignalHandler.h
 include/libdap/SignalHandlerRegisteredErr.h
 include/libdap/StdinResponse.h
 include/libdap/Str.h
 include/libdap/Structure.h
 include/libdap/Type.h
 include/libdap/UInt16.h
 include/libdap/UInt32.h
 include/libdap/UInt64.h
 include/libdap/UnMarshaller.h
 include/libdap/Url.h
 include/libdap/Vector.h
 include/libdap/XDRFileMarshaller.h
 include/libdap/XDRFileUnMarshaller.h
 include/libdap/XDRStreamMarshaller.h
 include/libdap/XDRStreamUnMarshaller.h
 include/libdap/XDRUtils.h
 include/libdap/XMLWriter.h
 include/libdap/ce_parser.h
 include/libdap/cgi_util.h
 include/libdap/chunked_istream.h
 include/libdap/chunked_ostream.h
 include/libdap/chunked_stream.h
 include/libdap/crc.h
 include/libdap/debug.h
 include/libdap/dods-datatypes.h
 include/libdap/dods-limits.h
 include/libdap/escaping.h
 include/libdap/expr.h
 include/libdap/media_types.h
 include/libdap/mime_util.h
 include/libdap/parser-util.h
 include/libdap/parser.h
 include/libdap/test/D4TestFunction.h
 include/libdap/test/D4TestTypeFactory.h
 include/libdap/test/TestArray.h
 include/libdap/test/TestByte.h
 include/libdap/test/TestCommon.h
 include/libdap/test/TestD4Enum.h
 include/libdap/test/TestD4Group.h
 include/libdap/test/TestD4Opaque.h
 include/libdap/test/TestD4Sequence.h
 include/libdap/test/TestFloat32.h
 include/libdap/test/TestFloat64.h
 include/libdap/test/TestFunction.h
 include/libdap/test/TestGrid.h
 include/libdap/test/TestInt16.h
 include/libdap/test/TestInt32.h
 include/libdap/test/TestInt64.h
 include/libdap/test/TestInt8.h
 include/libdap/test/TestSequence.h
 include/libdap/test/TestStr.h
 include/libdap/test/TestStructure.h
 include/libdap/test/TestTypeFactory.h
 include/libdap/test/TestUInt16.h
 include/libdap/test/TestUInt32.h
 include/libdap/test/TestUInt64.h
 include/libdap/test/TestUrl.h
 include/libdap/util.h
 include/libdap/util_mit.h
 include/libdap/xdr-datatypes.h
 lib/libdap.a
 lib/libdap.so
 lib/libdap.so.27
-lib/libdap.so.27.1.1
+lib/libdap.so.27.2.0
 lib/libdapclient.a
 lib/libdapclient.so
 lib/libdapclient.so.6
-lib/libdapclient.so.6.1.11
+lib/libdapclient.so.6.2.0
 lib/libdapserver.a
 lib/libdapserver.so
 lib/libdapserver.so.7
-lib/libdapserver.so.7.6.11
+lib/libdapserver.so.7.7.0
 lib/libtest-types.a
 libdata/pkgconfig/libdap.pc
 libdata/pkgconfig/libdapclient.pc
 libdata/pkgconfig/libdapserver.pc
 share/aclocal/libdap.m4
 share/man/man1/dap-config.1.gz
 share/man/man1/getdap.1.gz
 share/man/man1/getdap4.1.gz