diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 539c4d4..f184fbb 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -249,7 +249,7 @@ jobs:
       if: runner.os != 'Windows'
       run: "rsync -azvP ctdeploy@cantera.org:. ${MW_HEADERS_DIR}"
     - name: Build the MATLAB recipe
-      run: conda build ./cantera-matlab -m ./.ci_support/conda_build_config.yaml
+      run: conda build --debug ./cantera-matlab -m ./.ci_support/conda_build_config.yaml
     - name: List package contents
       run: |
         find '${{ runner.os == 'Windows' && '/c/Miniconda3' || env.CONDA }}/conda-bld' -name \*cantera\*.tar.bz2 | while read -r file; do
diff --git a/cantera-matlab/build.sh b/cantera-matlab/build.sh
index 7ad6378..dd0037b 100644
--- a/cantera-matlab/build.sh
+++ b/cantera-matlab/build.sh
@@ -20,23 +20,31 @@ if [[ "${OSX_ARCH}" == "" ]]; then
     echo "debug = False" >> cantera.conf
     echo "logging = 'debug'" >> cantera.conf
 else
+    echo "CC = '${CLANG}'" >> cantera.conf
+    echo "CXX = '${CLANGXX}'" >> cantera.conf
     if [[ "${CONDA_BUILD_SYSROOT}" != "" ]]; then
-        echo "cc_flags = '-isysroot ${CONDA_BUILD_SYSROOT}'" >> cantera.conf
-        echo "no_debug_linker_flags = '-isysroot ${CONDA_BUILD_SYSROOT}'" >> cantera.conf
+        echo "cc_flags = '-isysroot ${CONDA_BUILD_SYSROOT} ${CFLAGS}'" >> cantera.conf
+        echo "no_debug_linker_flags = '${LDFLAGS} -isysroot ${CONDA_BUILD_SYSROOT}'" >> cantera.conf
+    else
+        echo "cc_flags = '${CFLAGS}'" >> cantera.conf
+        echo "no_debug_linker_flags = '${LDFLAGS}'" >> cantera.conf
     fi
     echo "optimize_flags = ''" >> cantera.conf
     echo "debug = False" >> cantera.conf
 
-    echo "use_rpath_linkage = False" >> cantera.conf
     echo "logging = 'debug'" >> cantera.conf
+    echo "use_rpath_linkage = False" >> cantera.conf
 fi
 
 echo "matlab_toolbox = 'y'" >> cantera.conf
 echo "matlab_path = '${MW_HEADERS_DIR}'" >> cantera.conf
 
+echo "extra_inc_dirs = '${PREFIX}/include'" >> cantera.conf
+echo "extra_lib_dirs = '${PREFIX}/lib'" >> cantera.conf
+
 set -xe
 
-${BUILD_PREFIX}/bin/python ${BUILD_PREFIX}/bin/scons install
+${BUILD_PREFIX}/bin/python `which scons` install -j${CPU_COUNT}
 
 # "Install" just the Matlab interface. This method should
 # prevent this package from clobbering any existing