diff --git a/.github/workflows/ci-lazypg.yml b/.github/workflows/ci-lazypg.yml
index c11ac9104..fbff5f858 100644
--- a/.github/workflows/ci-lazypg.yml
+++ b/.github/workflows/ci-lazypg.yml
@@ -32,11 +32,16 @@ jobs:
           - os: macos-14
             cc: clang
             pg: 17
-#         - os: windows-latest
-#           cc: msvc
-#         - os: windows-latest
-#           cc: mingw
+          - os: windows-latest
+            cc: msvc
+          - os: windows-latest
+            cc: mingw
         java: [11, 17, 21, 23]
+        exclude:
+          - oscc: {os: windows-latest}
+            java: 17
+          - oscc: {os: windows-latest}
+            java: 23
 
     steps:
 
@@ -86,7 +91,8 @@ jobs:
           echo >>"$GITHUB_ENV" "ABS_JSHELL=$JAVA_HOME/bin/jshell"
         fi
 
-    - name: Set PGCONFIG in environment, installing PostgreSQL if needed
+    - name: Set PGCONFIG in environment, getting PostgreSQL if needed (!mingw)
+      if: ${{ 'mingw' != matrix.oscc.cc }}
       shell: bash
       env:
         PGVER: ${{ matrix.oscc.pg }}
@@ -111,6 +117,15 @@ jobs:
           echo >>"$GITHUB_ENV" PGCONFIG="$pfx/bin/pg_config"
         fi
 
+    - name: Set PGCONFIG in environment, getting gcc and PostgreSQL (mingw)
+      if: ${{ 'mingw' == matrix.oscc.cc }}
+      shell: C:\shells\msys2bash.cmd {0}
+      run: |
+        pacman -S --noconfirm \
+          mingw-w64-x86_64-gcc \
+          mingw-w64-x86_64-postgresql
+        echo >>"$GITHUB_ENV" PGCONFIG='c:\msys64\mingw64\bin\pg_config'
+
     - name: Report Java, Maven, and PostgreSQL versions
       shell: bash
       run: |
@@ -170,6 +185,22 @@ jobs:
       with:
         path: pljava
 
+    - name: Set plethora of MSVC environment variables (Windows MSVC)
+      if: ${{ 'Windows' == runner.os && 'msvc' == matrix.oscc.cc }}
+      uses: ilammy/msvc-dev-cmd@0b201ec74fa43914dc39ae48a89fd1d8cb592756
+
+    - name: Build PL/Java (Windows MSVC)
+      if: ${{ 'Windows' == runner.os && 'msvc' == matrix.oscc.cc }}
+      working-directory: pljava
+      # shell: cmd because of the issue described for ilammy/msvc-dev-cmd
+      # with Actions bash prepending stuff to the just-carefully-created PATH
+      shell: cmd
+      run: |
+        mvn clean install --batch-mode ^
+          -Dpgsql.pgconfig="%PGCONFIG%" ^
+          -Psaxon-examples -Ppgjdbc ^
+          -Dorg.slf4j.simpleLogger.log.org.apache.maven.cli.transfer.Slf4jMavenTransferListener=warn
+
     - name: Build PL/Java (Linux, macOS)
       if: ${{ 'Windows' != runner.os }}
       working-directory: pljava
@@ -182,46 +213,9 @@ jobs:
     - name: Build PL/Java (Windows MinGW-w64)
       if: ${{ 'Windows' == runner.os && 'mingw' == matrix.oscc.cc }}
       working-directory: pljava
-      #
-      # GitHub Actions will allow 'bash' as a shell choice, even on a Windows
-      # runner, in which case it's the bash from Git for Windows. That isn't the
-      # same as the msys64\usr\bin\bash that we want; what's more, while both
-      # rely on a cygwin DLL, they don't rely on the same one, and an attempt
-      # to exec one from the other leads to a "fatal error - cygheap base
-      # mismatch". So, the bash we want has to be started by something other
-      # than the bash we've got. In this case, set shell: to a command that
-      # will use cmd to start the right bash.
-      #
-      # Some of the MinGW magic is set up by the bash profile run at "login", so
-      # bash must be started with -l. That profile ends with a cd $HOME, so to
-      # avoid changing the current directory, set HOME=. first (credit for that:
-      # https://superuser.com/a/806371). As set above, . is really the pljava
-      # working-directory, so the bash script should start by resetting HOME to
-      # the path of its parent.
-      #
-      # The runner is provisioned with a very long PATH that includes separate
-      # bin directories for pre-provisioned packages. The MinGW profile replaces
-      # that with a much shorter path, so mvn and pg_config below must be given
-      # as absolute paths (using M2 and PGBIN supplied in the environment) or
-      # they won't be found. As long as mvn itself can be found, it is able
-      # to find java without difficulty, using the JAVA_HOME that is also in
-      # the environment.
-      #
-      # Those existing variables in the environment are all spelled in Windows
-      # style with drive letters, colons, and backslashes, rather than the MinGW
-      # unixy style, but the mingw bash doesn't seem to object.
-      #
-      # If you use the runner-supplied bash to examine the environment, you will
-      # see MSYSTEM=MINGW64 already in it, but that apparently is something the
-      # runner-supplied bash does. It must be set here before invoking the MinGW
-      # bash directly.
-      #
-      env:
-        HOME: .
-        MSYSTEM: MINGW64
-      shell: 'cmd /C "c:\msys64\usr\bin\bash -l "{0}""'
+      shell: C:\shells\msys2bash.cmd {0}
       run: |
-        HOME=$( (cd .. && pwd) )
+        PATH='/c/msys64/mingw64/bin:'"$PATH"
         "$M2"/mvn clean install --batch-mode \
           -Dpgsql.pgconfig="$PGCONFIG" \
           -Psaxon-examples -Ppgjdbc \
diff --git a/CI/integration b/CI/integration
index 21ac72516..fd8da7676 100644
--- a/CI/integration
+++ b/CI/integration
@@ -123,7 +123,7 @@ Path libjvm = (
   ? Stream.of("libjli.dylib", "jli/libjli.dylib")
     .map(s -> javaLibDir.resolve(s))
     .filter(Files::exists).findFirst().get()
-  : javaLibDir.resolve(s_isWindows ? "jvm.dll" : "server/libjvm.so")
+  : javaLibDir.resolve(s_isWindows ? "server\\jvm.dll" : "server/libjvm.so")
 );
 
 // Use deprecated major() here because feature() first appears in Java 10