diff --git a/Objects/frameobject.c b/Objects/frameobject.c
index 5b2f308..0491334 100644
--- a/Objects/frameobject.c
+++ b/Objects/frameobject.c
@@ -70,7 +70,7 @@
 	int new_iblock = 0;		/* The new value of f_iblock */
 	unsigned char *code = NULL;	/* The bytecode for the frame... */
 	Py_ssize_t code_len = 0;	/* ...and its length */
-	char *lnotab = NULL;		/* Iterating over co_lnotab */
+	unsigned char *lnotab = NULL;	/* Iterating over co_lnotab */
 	Py_ssize_t lnotab_len = 0;	/* (ditto) */
 	int offset = 0;			/* (ditto) */
 	int line = 0;			/* (ditto) */
@@ -114,7 +114,8 @@
 
 	/* Find the bytecode offset for the start of the given line, or the
 	 * first code-owning line after it. */
-	PyString_AsStringAndSize(f->f_code->co_lnotab, &lnotab, &lnotab_len);
+	PyString_AsStringAndSize((char*)f->f_code->co_lnotab,
+	                         &lnotab, &lnotab_len);
 	addr = 0;
 	line = f->f_code->co_firstlineno;
 	new_lasti = -1;