diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index cd852515..d945587a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -64,8 +64,8 @@ jobs:
       - name: Test
         run: ../../../b2 toolset=$TOOLSET
         working-directory: ../boost-root/libs/regex/test
-  ubuntu-focal-standalone:
-    runs-on: ubuntu-20.04
+  ubuntu-jammy-standalone:
+    runs-on: ubuntu-22.04
     strategy:
       fail-fast: false
       matrix:
@@ -87,7 +87,7 @@ jobs:
       - name: Install packages
         run: sudo apt install g++-9 g++-10
       - name: Test
-        run: ${{ matrix.compiler }} -std=${{ matrix.standard }}  -I../../include *.cpp ../../src/*.cpp -o regress -licuuc -licudata -licui18n && ./regress
+        run: ${{ matrix.compiler }} -std=${{ matrix.standard }}  -I../../include *.cpp ../../src/*.cpp -o regress -licuuc -licui18n && ./regress
         working-directory: ./test/regress
   ubuntu-bionic:
     runs-on: ubuntu-18.04
diff --git a/src/posix_api.cpp b/src/posix_api.cpp
index f34a5a16..131171ab 100644
--- a/src/posix_api.cpp
+++ b/src/posix_api.cpp
@@ -180,7 +180,7 @@ BOOST_REGEX_DECL regsize_t BOOST_REGEX_CCALL regerrorA(int code, const regex_tA*
             // We're converting an integer i to a string, and since i <= REG_E_UNKNOWN
             // a five character string is *always* large enough:
             //
-#if BOOST_CXX_VERSION >= 201103
+#if !defined(BOOST_CXX_VERSION) || (BOOST_CXX_VERSION >= 201103)
             int r = (std::snprintf)(localbuf, 5, "%d", i);
 #elif BOOST_WORKAROUND(BOOST_MSVC, >= 1400) && !defined(_WIN32_WCE) && !defined(UNDER_CE)
             int r = (::sprintf_s)(localbuf, 5, "%d", i);
@@ -194,7 +194,7 @@ BOOST_REGEX_DECL regsize_t BOOST_REGEX_CCALL regerrorA(int code, const regex_tA*
             return std::strlen(localbuf) + 1;
          }
       }
-#if BOOST_CXX_VERSION >= 201103
+#if  !defined(BOOST_CXX_VERSION) || (BOOST_CXX_VERSION >= 201103)
       int r = (::snprintf)(localbuf, 5, "%d", 0);
 #elif BOOST_WORKAROUND(BOOST_MSVC, >= 1400) && !defined(_WIN32_WCE) && !defined(UNDER_CE)
       int r = (::sprintf_s)(localbuf, 5, "%d", 0);