diff --git a/ports/libmodbus/CMakeLists.txt b/ports/libmodbus/CMakeLists.txt
deleted file mode 100644
index 618ba5f6cb..0000000000
--- a/ports/libmodbus/CMakeLists.txt
+++ /dev/null
@@ -1,114 +0,0 @@
-cmake_minimum_required(VERSION 3.0)
-project(libmodbus VERSION 3.1.6)
-
-set(LIBMODBUS_VERSION ${PROJECT_VERSION})
-set(LIBMODBUS_VERSION_MAJOR ${PROJECT_VERSION_MAJOR})
-set(LIBMODBUS_VERSION_MINOR ${PROJECT_VERSION_MINOR})
-set(LIBMODBUS_VERSION_MICRO ${PROJECT_VERSION_PATCH})
-configure_file(src/modbus-version.h.in ${CMAKE_CURRENT_BINARY_DIR}/modbus-version.h)
-
-if(WIN32)
-  set(HAVE_ERRNO_H 1)
-  set(HAVE_FCNTL_H 1)
-  set(HAVE_LIMITS_H 1)
-  set(HAVE_SYS_TYPES_H 1)
-  set(HAVE_TIME_H 1)
-  set(HAVE_MALLOC 1)
-  set(HAVE_MEMSET 1)
-  set(HAVE_STRERROR 1)
-else()
-  include(CheckIncludeFile)
-  check_include_file(arpa/inet.h HAVE_ARPA_INET_H)
-  check_include_file(byteswap.h HAVE_BYTESWAP_H)
-  check_include_file(errno.h HAVE_ERRNO_H)
-  check_include_file(fcntl.h HAVE_FCNTL_H)
-  check_include_file(limits.h HAVE_LIMITS_H)
-  check_include_file(linux/serial.h HAVE_LINUX_SERIAL_H)
-  check_include_file(netdb.h HAVE_NETDB_H)
-  check_include_file(netinet/in.h HAVE_NETINET_IN_H)
-  check_include_file(netinet/tcp.h HAVE_NETINET_TCP_H)
-  check_include_file(sys/ioctl.h HAVE_SYS_IOCTL_H)
-  check_include_file(sys/params.h HAVE_SYS_PARAMS_H)
-  check_include_file(sys/socket.h HAVE_SYS_SOCKET_H)
-  check_include_file(sys/time.h HAVE_SYS_TIME_H)
-  check_include_file(sys/types.h HAVE_SYS_TYPES_H)
-  check_include_file(termios.h HAVE_TERMIOS_H)
-  check_include_file(time.h HAVE_TIME_H)
-  check_include_file(unistd.h HAVE_UNISTD_H)
-
-  include(CheckFunctionExists)
-  check_function_exists(accept4 HAVE_ACCEPT4)
-  check_function_exists(fork HAVE_FORK)
-  check_function_exists(getaddrinfo HAVE_GETADDRINFO)
-  check_function_exists(gettimeofday HAVE_GETTIMEOFDAY)
-  check_function_exists(inet_ntoa HAVE_INET_NTOA)
-  check_function_exists(malloc HAVE_MALLOC)
-  check_function_exists(memset HAVE_MEMSET)
-  check_function_exists(select HAVE_SELECT)
-  check_function_exists(socket HAVE_SOCKET)
-  check_function_exists(strerror HAVE_STRERROR)
-  check_function_exists(strlcpy HAVE_STRLCPY)
-
-  include(CheckSymbolExists)
-  check_symbol_exists(TIOCSRS485 sys/ioctl.h HAVE_TIOCRS485)
-  check_symbol_exists(TIOCM_RTS sys/ioctl.h HAVE_TIOCM_RTS)
-endif()
-
-configure_file(config.h.cmake ${CMAKE_CURRENT_BINARY_DIR}/config.h)
-
-
-if(BUILD_SHARED_LIBS)
-  add_compile_options(-DDLLBUILD=ON)
-else()
-  add_compile_options(-DLIBBUILD=ON)
-endif()
-
-set(MODBUS_PUBLIC_HEADERS
-  src/modbus-rtu.h
-  src/modbus-tcp.h
-  src/modbus.h
-  ${CMAKE_CURRENT_BINARY_DIR}/modbus-version.h
-)
-
-add_library(modbus
-  src/modbus-data.c
-  src/modbus-rtu.c
-  src/modbus-tcp.c
-src/modbus.c)
-
-target_include_directories(modbus PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
-target_include_directories(modbus INTERFACE
-  $<INSTALL_INTERFACE:include>
-)
-set_target_properties(modbus PROPERTIES PUBLIC_HEADER "${MODBUS_PUBLIC_HEADERS}")
-
-if(CMAKE_COMPILER_IS_GNUCC)
-  target_compile_options(modbus PRIVATE -D_GNU_SOURCE)
-endif()
-
-if(WIN32)
-  target_link_libraries(modbus  wsock32 ws2_32)
-endif()
-
-set(LIBMODBUS_SOVERSION_VERSION 5.1.0)
-set(LIBMODBUS_SOVERSION_SOVERSION 5)
-
-
-set_target_properties(modbus PROPERTIES
-  VERSION ${LIBMODBUS_SOVERSION_VERSION}
-SOVERSION ${LIBMODBUS_SOVERSION_SOVERSION})
-
-
-install(
-  TARGETS modbus
-  EXPORT libmodbusConfig
-  RUNTIME DESTINATION bin
-  LIBRARY DESTINATION lib
-  ARCHIVE DESTINATION lib
-)
-install(EXPORT libmodbusConfig DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake)
-
-
-if(NOT DISABLE_INSTALL_HEADERS)
-  install(FILES ${MODBUS_PUBLIC_HEADERS} DESTINATION include/)
-endif()
diff --git a/ports/libmodbus/cflags.diff b/ports/libmodbus/cflags.diff
new file mode 100644
index 0000000000..854aca246b
--- /dev/null
+++ b/ports/libmodbus/cflags.diff
@@ -0,0 +1,20 @@
+diff --git a/configure.ac b/configure.ac
+index 920612f..06d5dfa 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -147,6 +147,7 @@ AC_CHECK_DECLS([TIOCSRS485], [], [], [[#include <sys/ioctl.h>]])
+ # Check for RTS flags
+ AC_CHECK_DECLS([TIOCM_RTS], [], [], [[#include <sys/ioctl.h>]])
+ 
++test -n "$WARNING_CFLAGS" || \
+ WARNING_CFLAGS="-Wall \
+ -Wmissing-declarations -Wmissing-prototypes \
+ -Wnested-externs -Wpointer-arith \
+@@ -178,6 +179,7 @@ AC_ARG_ENABLE([debug],
+   [enable_debug=$enableval],
+   [enable_debug=no])
+ 
++test -n "$CFLAGS" || \
+ AS_IF([test "x$enable_debug" = "xyes"], [
+   CFLAGS="-g -O0"
+   CXXFLAGS="-g -O0"
diff --git a/ports/libmodbus/config.h.cmake b/ports/libmodbus/config.h.cmake
deleted file mode 100644
index b8f7585be7..0000000000
--- a/ports/libmodbus/config.h.cmake
+++ /dev/null
@@ -1,49 +0,0 @@
-#ifndef CONFIG_H
-#define CONFIG_H
-
-#cmakedefine HAVE_ARPA_INET_H
-#cmakedefine HAVE_BYTESWAP_H
-#cmakedefine HAVE_ERRNO_H
-#cmakedefine HAVE_FCNTL_H
-#cmakedefine HAVE_LIMITS_H
-#cmakedefine HAVE_LINUX_SERIAL_H
-#cmakedefine HAVE_NETDB_H
-#cmakedefine HAVE_NETINET_IN_H
-#cmakedefine HAVE_NETINET_TCP_H
-#cmakedefine HAVE_SYS_IOCTL_H
-#cmakedefine HAVE_SYS_PARAMS_H
-#cmakedefine HAVE_SYS_SOCKET_H
-#cmakedefine HAVE_SYS_TIME_H
-#cmakedefine HAVE_SYS_TYPES_H
-#cmakedefine HAVE_TERMIOS_H
-#cmakedefine HAVE_TIME_H
-#cmakedefine HAVE_UNISTD_H
-
-#cmakedefine HAVE_ACCEPT4
-#cmakedefine HAVE_FORK
-#cmakedefine HAVE_GETADDRINFO
-#cmakedefine HAVE_GETTIMEOFDAY
-#cmakedefine HAVE_INET_NTOA
-#cmakedefine HAVE_MALLOC
-#cmakedefine HAVE_MEMSET
-#cmakedefine HAVE_SELECT
-#cmakedefine HAVE_SOCKET
-#cmakedefine HAVE_STRERROR
-#cmakedefine HAVE_STRLCPY
-
-#cmakedefine HAVE_TIOCRS485
-#cmakedefine HAVE_TIOCM_RTS
-
-#ifdef HAVE_TIOCM_RTS
-#define HAVE_DECL_TIOCM_RTS 1
-#else
-#define HAVE_DECL_TIOCM_RTS 0
-#endif
-
-#ifdef HAVE_TIOCRS485
-#define HAVE_DECL_TIOCSRS485 1
-#else
-#define HAVE_DECL_TIOCSRS485 0
-#endif
-
-#endif
\ No newline at end of file
diff --git a/ports/libmodbus/fix-static-linkage.patch b/ports/libmodbus/fix-static-linkage.patch
deleted file mode 100644
index 7d7ae79f50..0000000000
--- a/ports/libmodbus/fix-static-linkage.patch
+++ /dev/null
@@ -1,13 +0,0 @@
-diff --git a/src/modbus.h b/src/modbus.h
-index fbe20bc..895d05d 100644
---- a/src/modbus.h
-+++ b/src/modbus.h
-@@ -24,6 +24,8 @@
- # if defined(DLLBUILD)
- /* define DLLBUILD when building the DLL */
- #  define MODBUS_API __declspec(dllexport)
-+# elif defined(LIBBUILD)
-+#  define MODBUS_API
- # else
- #  define MODBUS_API __declspec(dllimport)
- # endif
diff --git a/ports/libmodbus/libmodbusConfig.cmake b/ports/libmodbus/libmodbusConfig.cmake
new file mode 100644
index 0000000000..83aebe4e81
--- /dev/null
+++ b/ports/libmodbus/libmodbusConfig.cmake
@@ -0,0 +1,27 @@
+message(WARNING "find_package(modbus) is unofficial. libmodbus provides a pkg-config module: libmodbus")
+
+if(NOT TARGET modbus)
+    get_filename_component(VCPKG_IMPORT_PREFIX "${CMAKE_CURRENT_LIST_DIR}/../.." ABSOLUTE)
+    find_library(Z_VCPKG_MODBUS_RELEASE NAMES modbus PATHS "${VCPKG_IMPORT_PREFIX}/lib" REQUIRED)
+    find_library(Z_VCPKG_MODBUS_DEBUG NAMES modbus PATHS "${VCPKG_IMPORT_PREFIX}/debug/lib")
+    mark_as_advanced(Z_VCPKG_MODBUS_RELEASE Z_VCPKG_MODBUS_DEBUG)
+    add_library(modbus UNKNOWN IMPORTED)
+    set_target_properties(modbus PROPERTIES
+        IMPORTED_CONFIGURATIONS "Release"
+        INTERFACE_INCLUDE_DIRECTORIES "${VCPKG_IMPORT_PREFIX}/include/modbus"
+        IMPORTED_LOCATION_RELEASE "${Z_VCPKG_MODBUS_RELEASE}"
+        IMPORTED_LINK_INTERFACE_LANGUAGES_RELEASE "C"
+    )
+    if(Z_VCPKG_MODBUS_DEBUG)
+        set_property(TARGET modbus APPEND PROPERTY IMPORTED_CONFIGURATIONS Debug)
+        set_target_properties(modbus PROPERTIES
+            IMPORTED_LOCATION_DEBUG "${Z_VCPKG_MODBUS_DEBUG}"
+            IMPORTED_LINK_INTERFACE_LANGUAGES_DEBUG "C"
+        )
+    endif()
+    if(WIN32)
+        set_target_properties(modbus PROPERTIES
+            INTERFACE_LINK_LIBRARIES "ws2_32"
+        )
+    endif()
+endif()
diff --git a/ports/libmodbus/library-linkage.diff b/ports/libmodbus/library-linkage.diff
new file mode 100644
index 0000000000..402363dfcc
--- /dev/null
+++ b/ports/libmodbus/library-linkage.diff
@@ -0,0 +1,32 @@
+diff --git a/configure.ac b/configure.ac
+index 9f30d29..29737da 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -120,6 +120,14 @@ AC_C_INLINE
+ # libtool
+ AC_PROG_CXX
+ 
++if "$os_win32" = "true"; then
++  if test "$enable_shared" = "yes"; then
++    AC_DEFINE(DLLBUILD, [], [Building a DLL])
++  else
++    AC_DEFINE(STATIC_LIBMODBUS, [], [Building a static library])
++  fi
++fi
++
+ # Various types
+ AC_TYPE_INT64_T
+ AC_TYPE_SIZE_T
+diff --git a/src/modbus.h b/src/modbus.h
+index fa7ec4a..ae204ce 100644
+--- a/src/modbus.h
++++ b/src/modbus.h
+@@ -25,6 +25,8 @@
+ # if defined(DLLBUILD)
+ /* define DLLBUILD when building the DLL */
+ #  define MODBUS_API __declspec(dllexport)
++# elif defined(STATIC_LIBMODBUS)
++#  define MODBUS_API
+ # else
+ #  define MODBUS_API __declspec(dllimport)
+ # endif
diff --git a/ports/libmodbus/pkgconfig.diff b/ports/libmodbus/pkgconfig.diff
new file mode 100644
index 0000000000..015d84ce66
--- /dev/null
+++ b/ports/libmodbus/pkgconfig.diff
@@ -0,0 +1,23 @@
+diff --git a/configure.ac b/configure.ac
+index 06d5dfa..f3122ac 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -133,6 +133,8 @@ if test "$os_cygwin" = "false"; then
+     AC_CHECK_HEADERS([winsock2.h], HAVE_WINSOCK2_H=yes)
+     if test "x$HAVE_WINSOCK2_H" = "xyes"; then
+         LIBS="$LIBS -lws2_32"
++        PC_LIBS_PRIVATE="$PC_LIBS_PRIVATE -lws2_32"
++        AC_SUBST(PC_LIBS_PRIVATE)
+     AC_SUBST(LIBS)
+     fi
+ fi
+diff --git a/libmodbus.pc.in b/libmodbus.pc.in
+index f1a9cbf..f7b4d08 100644
+--- a/libmodbus.pc.in
++++ b/libmodbus.pc.in
+@@ -7,4 +7,5 @@ Name: modbus
+ Description: Modbus library
+ Version: @VERSION@
+ Libs: -L${libdir} -lmodbus
++Libs.private: @PC_LIBS_PRIVATE@
+ Cflags: -I${includedir}/modbus
diff --git a/ports/libmodbus/portfile.cmake b/ports/libmodbus/portfile.cmake
index 3e16315905..117f36621a 100644
--- a/ports/libmodbus/portfile.cmake
+++ b/ports/libmodbus/portfile.cmake
@@ -2,30 +2,37 @@ vcpkg_from_github(
     OUT_SOURCE_PATH SOURCE_PATH
     REPO stephane/libmodbus
     REF "v${VERSION}"
-    SHA512 6a01da1f8b486e356ff44874f1479d9d121463958a5ed06e60d910328ccc9b2d431b4a1fd72861c5c645c97b5887a076b763ad6a9ae6b18402dd043ec525b1e2
+    SHA512 cb506d5b72b629591002450221ea512a067209ee60c588dc88c45494ea983af2c05c47b2d0ba7db02e46d7a30110547ec96f9f98d643756f9528a99291683f70
     HEAD_REF master
-    PATCHES fix-static-linkage.patch
+    PATCHES
+        cflags.diff
+        library-linkage.diff
+        pkgconfig.diff
+        ssize_t.diff
 )
 
-file(COPY "${CMAKE_CURRENT_LIST_DIR}/CMakeLists.txt" "${CMAKE_CURRENT_LIST_DIR}/config.h.cmake"
-     DESTINATION "${SOURCE_PATH}"
-)
-
-vcpkg_cmake_configure(
-    SOURCE_PATH "${SOURCE_PATH}"
-    OPTIONS_DEBUG
-        -DDISABLE_INSTALL_HEADERS=ON
-)
-
-vcpkg_cmake_install()
-vcpkg_copy_pdbs()
-vcpkg_cmake_config_fixup(CONFIG_PATH lib/cmake)
-
-if(VCPKG_TARGET_IS_WINDOWS AND VCPKG_LIBRARY_LINKAGE STREQUAL "static")
-    vcpkg_replace_string("${CURRENT_PACKAGES_DIR}/include/modbus.h" "elif defined(LIBBUILD)" "elif 1")
+if(VCPKG_TARGET_IS_WINDOWS AND NOT VCPKG_TARGET_IS_MINGW)
+    set(ENV{WARNING_CFLAGS} "-D_CRT_SECURE_NO_DEPRECATE=1 -D_CRT_NONSTDC_NO_DEPRECATE=1")
 endif()
 
-# Handle copyright
-vcpkg_install_copyright(FILE_LIST "${SOURCE_PATH}/COPYING.LESSER")
+vcpkg_make_configure(
+    SOURCE_PATH "${SOURCE_PATH}"
+    AUTORECONF
+    OPTIONS
+        --enable-tests=no
+)
+vcpkg_make_install()
+vcpkg_copy_pdbs()
+vcpkg_fixup_pkgconfig()
+file(COPY "${CURRENT_PORT_DIR}/libmodbusConfig.cmake" DESTINATION "${CURRENT_PACKAGES_DIR}/share/libmodbus")
 
-file(REMOVE_RECURSE "${CURRENT_PACKAGES_DIR}/debug/include")
+if(VCPKG_TARGET_IS_WINDOWS AND VCPKG_LIBRARY_LINKAGE STREQUAL "static")
+    vcpkg_replace_string("${CURRENT_PACKAGES_DIR}/include/modbus/modbus.h" "defined(STATIC_LIBMODBUS)" "1")
+endif()
+
+ file(REMOVE_RECURSE
+    "${CURRENT_PACKAGES_DIR}/debug/include"
+    "${CURRENT_PACKAGES_DIR}/debug/share"
+)
+
+vcpkg_install_copyright(FILE_LIST "${SOURCE_PATH}/COPYING.LESSER")
diff --git a/ports/libmodbus/ssize_t.diff b/ports/libmodbus/ssize_t.diff
new file mode 100644
index 0000000000..e2ba0c3dac
--- /dev/null
+++ b/ports/libmodbus/ssize_t.diff
@@ -0,0 +1,14 @@
+diff --git a/src/modbus-private.h b/src/modbus-private.h
+index ea83187..db5a3dc 100644
+--- a/src/modbus-private.h
++++ b/src/modbus-private.h
+@@ -14,7 +14,9 @@
+ #else
+ # include "stdint.h"
+ # include <time.h>
++# ifndef ssize_t
+ typedef int ssize_t;
++# endif
+ #endif
+ // clang-format on
+ #include <config.h>
diff --git a/ports/libmodbus/vcpkg.json b/ports/libmodbus/vcpkg.json
index 1f383188a3..2dbc876865 100644
--- a/ports/libmodbus/vcpkg.json
+++ b/ports/libmodbus/vcpkg.json
@@ -1,17 +1,13 @@
 {
   "name": "libmodbus",
-  "version": "3.1.10",
+  "version": "3.1.11",
   "description": "libmodbus is a free software library to send/receive data with a device which respects the Modbus protocol",
   "homepage": "https://github.com/stephane/libmodbus",
   "license": "LGPL-2.1-or-later",
   "supports": "!uwp & !xbox",
   "dependencies": [
     {
-      "name": "vcpkg-cmake",
-      "host": true
-    },
-    {
-      "name": "vcpkg-cmake-config",
+      "name": "vcpkg-make",
       "host": true
     }
   ]
diff --git a/scripts/test_ports/vcpkg-ci-libmodbus/portfile.cmake b/scripts/test_ports/vcpkg-ci-libmodbus/portfile.cmake
new file mode 100644
index 0000000000..dd25706120
--- /dev/null
+++ b/scripts/test_ports/vcpkg-ci-libmodbus/portfile.cmake
@@ -0,0 +1,10 @@
+set(VCPKG_POLICY_EMPTY_PACKAGE enabled)
+
+vcpkg_find_acquire_program(PKGCONFIG)
+
+vcpkg_cmake_configure(
+    SOURCE_PATH "${CURRENT_PORT_DIR}/project"
+    OPTIONS
+        "-DPKG_CONFIG_EXECUTABLE=${PKGCONFIG}"
+)
+vcpkg_cmake_build()
diff --git a/scripts/test_ports/vcpkg-ci-libmodbus/project/CMakeLists.txt b/scripts/test_ports/vcpkg-ci-libmodbus/project/CMakeLists.txt
new file mode 100644
index 0000000000..b4a85a0fd2
--- /dev/null
+++ b/scripts/test_ports/vcpkg-ci-libmodbus/project/CMakeLists.txt
@@ -0,0 +1,16 @@
+cmake_minimum_required(VERSION 3.30)
+project(libmodbus-test C)
+
+find_package(libmodbus CONFIG REQUIRED)
+add_library(imported::modbus ALIAS modbus)
+
+add_executable(main main.c)
+target_link_libraries(main PRIVATE imported::modbus)
+
+find_package(PkgConfig REQUIRED)
+pkg_check_modules(libmodbus_pc libmodbus REQUIRED IMPORTED_TARGET)
+
+add_executable(main-pkconfig main.c)
+target_link_libraries(main-pkconfig PRIVATE
+    PkgConfig::libmodbus_pc
+)
diff --git a/scripts/test_ports/vcpkg-ci-libmodbus/project/main.c b/scripts/test_ports/vcpkg-ci-libmodbus/project/main.c
new file mode 100644
index 0000000000..aaffb06b36
--- /dev/null
+++ b/scripts/test_ports/vcpkg-ci-libmodbus/project/main.c
@@ -0,0 +1,12 @@
+#include <stdio.h>
+#include <modbus.h>
+
+int main()
+{
+    modbus_t *ctx = modbus_new_rtu("/dev/ttyUSB0", 115200, 'N', 8, 1);
+    if (ctx == NULL) {
+        fprintf(stderr, "Unable to create the libmodbus context\n");
+        return -1;
+    }
+    return 0;
+}
diff --git a/scripts/test_ports/vcpkg-ci-libmodbus/vcpkg.json b/scripts/test_ports/vcpkg-ci-libmodbus/vcpkg.json
new file mode 100644
index 0000000000..293ffea3cb
--- /dev/null
+++ b/scripts/test_ports/vcpkg-ci-libmodbus/vcpkg.json
@@ -0,0 +1,17 @@
+{
+  "name": "vcpkg-ci-libmodbus",
+  "version-string": "ci",
+  "description": "Port to validate libmodbus in CI",
+  "homepage": "https://github.com/microsoft/vcpkg",
+  "license": "MIT",
+  "dependencies": [
+    {
+      "name": "libmodbus",
+      "default-features": false
+    },
+    {
+      "name": "vcpkg-cmake",
+      "host": true
+    }
+  ]
+}
diff --git a/versions/baseline.json b/versions/baseline.json
index 5a15e5ba5b..76bde6add2 100644
--- a/versions/baseline.json
+++ b/versions/baseline.json
@@ -4973,7 +4973,7 @@
       "port-version": 13
     },
     "libmodbus": {
-      "baseline": "3.1.10",
+      "baseline": "3.1.11",
       "port-version": 0
     },
     "libmodman": {
diff --git a/versions/l-/libmodbus.json b/versions/l-/libmodbus.json
index 8f80b0bcc6..908cd33ef8 100644
--- a/versions/l-/libmodbus.json
+++ b/versions/l-/libmodbus.json
@@ -1,5 +1,10 @@
 {
   "versions": [
+    {
+      "git-tree": "9830c2727d060b7b7a8bddf735d39118576419d8",
+      "version": "3.1.11",
+      "port-version": 0
+    },
     {
       "git-tree": "5af2a746eeb644d4c228d03f4bb7854cf4f5691b",
       "version": "3.1.10",