diff --git a/lldb/scripts/Python/build-swig-Python.sh b/lldb/scripts/Python/build-swig-Python.sh
index efbc748..96c4b2b 100755
--- a/lldb/scripts/Python/build-swig-Python.sh
+++ b/lldb/scripts/Python/build-swig-Python.sh
@@ -46,6 +46,7 @@
 swig_python_extensions=${SRC_ROOT}/scripts/Python/python-extensions.swig
 swig_python_wrapper=${SRC_ROOT}/scripts/Python/python-wrapper.swig
 swig_python_typemaps=${SRC_ROOT}/scripts/Python/python-typemaps.swig
+swig_python_swigsafecast=${SRC_ROOT}/scripts/Python/python-swigsafecast.swig
 
 if [ "$LLDB_DISABLE_PYTHON" = "1" ] ; then
     # We don't want Python for this build, but touch the output file so we don't have to
@@ -278,6 +279,19 @@
     fi
 fi
 
+if [ $NeedToUpdate -eq 0 ]
+then
+    if [ ${swig_python_swigsafecast} -nt ${swig_output_file} ]
+    then
+        NeedToUpdate=1
+        if [ $Debug -eq 1 ]
+        then
+            echo "${swig_python_swigsafecast} is newer than ${swig_output_file}"
+            echo "swig file will need to be re-built."
+        fi
+    fi
+fi
+
 python_version=`/usr/bin/env python --version 2>&1 | sed -e 's,Python ,,' -e 's,[.][0-9],,2' -e 's,[a-z][a-z][0-9],,'`
 
 if [ $MakefileCalled -eq 0 ]