diff --git a/meson_init.sh b/meson_init.sh
index 6f06bc9..34b25b7 100755
--- a/meson_init.sh
+++ b/meson_init.sh
@@ -19,16 +19,19 @@
 
   -f: Remove build directories before running Meson.
   -r: Force reconfiguration of build directories.
+  -K: Keep include search paths as generated by Meson.
 
 USAGE
 }
 
 FLAGS_force=false
 FLAGS_reconfigure=""
-while getopts 'r?:f?' flag; do
+FLAGS_keep_includes=false
+while getopts 'r?:f?:K?' flag; do
   case "${flag}" in
     f) FLAGS_force=true;;
     r) FLAGS_reconfigure="--reconfigure";;
+    K) FLAGS_keep_includes=true;;
     ?) usage && exit 1;;
     *) usage
        error "Unexpected option ${flag}"
@@ -69,8 +72,29 @@
   done
 fi
 
+# purge_includes $target deletes any -I command line arguments that are not
+# - Absolute paths.
+# - Ephemeral build directories.
+#
+# This function is necessary because Meson does not give adequate
+# control over what directories are passed in as -I search directories
+# to the C compiler. While Meson does provide |implicit_include_directories|,
+# support for this option is poor: empirically, Meson ignores this option for
+# some targerts. Doing it as a post-processing step ensures that Meson does
+# not allow improper #includes to compile successfully.
+function purge_includes() {
+  if [[ "${FLAGS_keep_includes}" == "true" ]]; then
+    return
+  fi
+  echo "Purging superfluous -I arguments from $1."
+  local ninja_file="${BUILD_DIR_PREFIX}-$1/build.ninja"
+  perl -pi -e 's#-I[^/][^@ ]+ # #g' -- "$ninja_file"
+}
+
 meson ${FLAGS_reconfigure} "-Dtarget=${TARGET_VERILATOR}" --cross-file=toolchain.txt \
     --buildtype=plain "${BUILD_DIR_PREFIX}-${TARGET_VERILATOR}"
+purge_includes ${TARGET_VERILATOR}
 
 meson ${FLAGS_reconfigure} "-Dtarget=${TARGET_FPGA}" --cross-file=toolchain.txt \
     --buildtype=plain "${BUILD_DIR_PREFIX}-${TARGET_FPGA}"
+purge_includes ${TARGET_FPGA}