Index: b/Modules/md5.c
===================================================================
--- a/Modules/md5.c
+++ b/Modules/md5.c
@@ -311,7 +311,7 @@ md5_process(md5_state_t *pms, const md5_
 }
 
 void
-md5_init(md5_state_t *pms)
+_Py_md5_init(md5_state_t *pms)
 {
     pms->count[0] = pms->count[1] = 0;
     pms->abcd[0] = 0x67452301;
@@ -321,7 +321,7 @@ md5_init(md5_state_t *pms)
 }
 
 void
-md5_append(md5_state_t *pms, const md5_byte_t *data, unsigned int nbytes)
+_Py_md5_append(md5_state_t *pms, const md5_byte_t *data, unsigned int nbytes)
 {
     const md5_byte_t *p = data;
     unsigned int left = nbytes;
@@ -338,8 +338,8 @@ md5_append(md5_state_t *pms, const md5_b
         /* handle the append in two steps to prevent overflow */
         overlap = 64 - offset;
 
-        md5_append(pms, data, overlap);
-        md5_append(pms, data + overlap, nbytes - overlap);
+        _Py_md5_append(pms, data, overlap);
+        _Py_md5_append(pms, data + overlap, nbytes - overlap);
         return;
     }
 
@@ -371,7 +371,7 @@ md5_append(md5_state_t *pms, const md5_b
 }
 
 void
-md5_finish(md5_state_t *pms, md5_byte_t digest[16])
+_Py_md5_finish(md5_state_t *pms, md5_byte_t digest[16])
 {
     static const md5_byte_t pad[64] = {
         0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
@@ -386,9 +386,9 @@ md5_finish(md5_state_t *pms, md5_byte_t
     for (i = 0; i < 8; ++i)
         data[i] = (md5_byte_t)(pms->count[i >> 2] >> ((i & 3) << 3));
     /* Pad to 56 bytes mod 64. */
-    md5_append(pms, pad, ((55 - (pms->count[0] >> 3)) & 63) + 1);
+    _Py_md5_append(pms, pad, ((55 - (pms->count[0] >> 3)) & 63) + 1);
     /* Append the length. */
-    md5_append(pms, data, 8);
+    _Py_md5_append(pms, data, 8);
     for (i = 0; i < 16; ++i)
         digest[i] = (md5_byte_t)(pms->abcd[i >> 2] >> ((i & 3) << 3));
 }
Index: b/Modules/md5.h
===================================================================
--- a/Modules/md5.h
+++ b/Modules/md5.h
@@ -76,13 +76,13 @@ extern "C"
 #endif
 
 /* Initialize the algorithm. */
-void md5_init(md5_state_t *pms);
+void _Py_md5_init(md5_state_t *pms);
 
 /* Append a string to the message. */
-void md5_append(md5_state_t *pms, const md5_byte_t *data, unsigned int nbytes);
+void _Py_md5_append(md5_state_t *pms, const md5_byte_t *data, unsigned int nbytes);
 
 /* Finish the message and return the digest. */
-void md5_finish(md5_state_t *pms, md5_byte_t digest[16]);
+void _Py_md5_finish(md5_state_t *pms, md5_byte_t digest[16]);
 
 #ifdef __cplusplus
 }  /* end extern "C" */
Index: b/Modules/md5module.c
===================================================================
--- a/Modules/md5module.c
+++ b/Modules/md5module.c
@@ -31,7 +31,7 @@ newmd5object(void)
     if (md5p == NULL)
         return NULL;
 
-    md5_init(&md5p->md5);       /* actual initialisation */
+    _Py_md5_init(&md5p->md5);       /* actual initialisation */
     return md5p;
 }
 
@@ -65,7 +65,7 @@ md5_update(md5object *self, PyObject *ar
             nbytes = INT_MAX;
         else
             nbytes = n;
-        md5_append(&self->md5, buf,
+        _Py_md5_append(&self->md5, buf,
                    Py_SAFE_DOWNCAST(nbytes, Py_ssize_t, unsigned int));
         buf += nbytes;
         n -= nbytes;
@@ -91,7 +91,7 @@ md5_digest(md5object *self)
 
     /* make a temporary copy, and perform the final */
     mdContext = self->md5;
-    md5_finish(&mdContext, aDigest);
+    _Py_md5_finish(&mdContext, aDigest);
 
     return PyString_FromStringAndSize((char *)aDigest, 16);
 }
@@ -114,7 +114,7 @@ md5_hexdigest(md5object *self)
 
     /* make a temporary copy, and perform the final */
     mdContext = self->md5;
-    md5_finish(&mdContext, digest);
+    _Py_md5_finish(&mdContext, digest);
 
     /* Make hex version of the digest */
     for(i=j=0; i<16; i++) {
@@ -294,7 +294,7 @@ MD5_new(PyObject *self, PyObject *args)
             nbytes = INT_MAX;
         else
             nbytes = n;
-        md5_append(&md5p->md5, buf,
+        _Py_md5_append(&md5p->md5, buf,
                    Py_SAFE_DOWNCAST(nbytes, Py_ssize_t, unsigned int));
         buf += nbytes;
         n -= nbytes;