diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index bd4f494..bdd9bd7 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -132,8 +132,8 @@
 	PyThreadState *tstate;
 	PyObject *bimod, *sysmod;
 	char *p;
-	char *icodeset; /* On Windows, input codeset may theoretically 
-			   differ from output codeset. */
+	char *icodeset = NULL; /* On Windows, input codeset may theoretically 
+			          differ from output codeset. */
 	char *codeset = NULL;
 	char *errors = NULL;
 	int free_codeset = 0;