diff --git a/Misc/NEWS b/Misc/NEWS
index 15e3401..87af173 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -16,6 +16,9 @@
 Library
 -------
 
+- Issue #4542: On Windows, binascii.crc32 still accepted str as binary input;
+  the corresponding tests now pass.
+
 - Issue #4537: webbrowser.UnixBrowser would fail to open the browser because
   it was calling the wrong open() function.
 
diff --git a/Modules/binascii.c b/Modules/binascii.c
index 52bd6dc..51101b4 100644
--- a/Modules/binascii.c
+++ b/Modules/binascii.c
@@ -1019,7 +1019,7 @@
 	Py_ssize_t len;
 	unsigned int result;
 
-	if ( !PyArg_ParseTuple(args, "s*|I:crc32", &pbin, &crc) )
+	if ( !PyArg_ParseTuple(args, "y*|I:crc32", &pbin, &crc) )
 		return NULL;
 	bin_data = pbin.buf;
 	len = pbin.len;