--- a/Python/initconfig.c
+++ b/Python/initconfig.c
@@ -120,7 +120,7 @@ int Py_NoSiteFlag = 0; /* Suppress 'impo
 int Py_BytesWarningFlag = 0; /* Warn on str(bytes) and str(buffer) */
 int Py_FrozenFlag = 0; /* Needed by getpath.c */
 int Py_IgnoreEnvironmentFlag = 0; /* e.g. PYTHONPATH, PYTHONHOME */
-int Py_DontWriteBytecodeFlag = 0; /* Suppress writing bytecode files (*.pyc) */
+int Py_DontWriteBytecodeFlag = 1; /* Suppress writing bytecode files (*.pyc) */
 int Py_NoUserSiteDirectory = 0; /* for -s and site.py */
 int Py_UnbufferedStdioFlag = 0; /* Unbuffered binary std{in,out,err} */
 int Py_HashRandomizationFlag = 0; /* for -R and PYTHONHASHSEED */
