diff --git a/recipe/activate.bat b/recipe/activate.bat
index ca83adc..fc0bcba 100755
--- a/recipe/activate.bat
+++ b/recipe/activate.bat
@@ -1,4 +1,5 @@
 @@echo on
+setlocal EnableDelayedExpansion
 
 :: Set env vars that tell distutils to use the compiler that we put on path
 SET DISTUTILS_USE_SDK=1
@@ -91,7 +92,7 @@ set "CMAKE_ARGS=-DCMAKE_BUILD_TYPE=Release"
 IF "%CONDA_BUILD%" == "1" (
   set "CMAKE_ARGS=%CMAKE_ARGS% -DCMAKE_INSTALL_PREFIX=%LIBRARY_PREFIX% -DCMAKE_PROGRAM_PATH=%BUILD_PREFIX%\bin;%BUILD_PREFIX%\Scripts;%BUILD_PREFIX%\Library\bin;%PREFIX%\bin;%PREFIX%\Scripts;%PREFIX%\Library\bin"
   :: see https://github.com/conda-forge/conda-smithy/issues/2319
-  set "CMAKE_ARGS=%CMAKE_ARGS% -DPython_FIND_REGISTRY=NEVER -DPython3_FIND_REGISTRY=NEVER"
+  set "CMAKE_ARGS=!CMAKE_ARGS! -DPython_FIND_REGISTRY=NEVER -DPython3_FIND_REGISTRY=NEVER"
 )
 
 IF NOT "@{target_platform}" == "@{host_platform}" (
diff --git a/recipe/meta.yaml b/recipe/meta.yaml
index d467198..e8587f1 100644
--- a/recipe/meta.yaml
+++ b/recipe/meta.yaml
@@ -18,7 +18,7 @@
 {% set vcvars_ver_maj = cl_version.split(".")[0]|int - 5 %}
 {% set vcvars_ver_min = cl_version.split(".")[1]|int %}
 {% set vcvars_ver = vcvars_ver_maj ~ "." ~ vcvars_ver_min %}
-{% set build_num = 28 %}
+{% set build_num = 29 %}
 
 package:
   name: vs{{ vsyear }}