diff --git a/vcbuild.bat b/vcbuild.bat
index b24572aba..6c105983c 100644
--- a/vcbuild.bat
+++ b/vcbuild.bat
@@ -9,6 +9,12 @@ echo Build type: %build_type%
 if not "%2"=="" (set arch=%2) else (set arch=x86_64)
 echo Arch: %arch%
 
+@rem Single source of truth for the targeted Visual Studio version: both the
+@rem Conan-side generator pin below and the CMake -G flag must agree, or
+@rem dependencies built from source (e.g. yajl, on --build=missing) can end
+@rem up configured under a different VS/CMake than the main project.
+set VS_GENERATOR=Visual Studio 17 2022
+
 if "%3"=="USE_ASAN" (
     echo Address Sanitizer: Enabled
     set CI_ASAN=-c tools.build:cxxflags="[""/fsanitize=address""]"
@@ -20,9 +26,11 @@ if "%3"=="USE_ASAN" (
 )
 
 cd build\win32
-conan install . -s compiler.cppstd=17 %CI_ASAN% --output-folder=build --build=missing --settings=build_type=%build_type% --settings=arch=%arch%
+@rem Pin Conan's own generator for dependency builds (e.g. yajl, built from
+@rem source on --build=missing) to VS_GENERATOR too -- see the note above.
+conan install . -s compiler.cppstd=17 %CI_ASAN% -c tools.cmake.cmaketoolchain:generator="%VS_GENERATOR%" --output-folder=build --build=missing --settings=build_type=%build_type% --settings=arch=%arch%
 cd build
-cmake --fresh .. -G "Visual Studio 17 2022" -DCMAKE_TOOLCHAIN_FILE=conan_toolchain.cmake -DUSE_ASAN=%ASAN_FLAG% %4 %5 %6 %7 %8 %9
+cmake --fresh .. -G "%VS_GENERATOR%" -DCMAKE_TOOLCHAIN_FILE=conan_toolchain.cmake -DUSE_ASAN=%ASAN_FLAG% %4 %5 %6 %7 %8 %9
 cmake --build . --config %build_type%
 
 popd