diff -r 464e8fd7300d Modules/readline.c
--- a/Modules/readline.c	Thu Jun 13 10:08:00 2013 +0300
+++ b/Modules/readline.c	Thu Jun 13 23:10:45 2013 +0200
@@ -1097,7 +1097,7 @@ call_readline(FILE *sys_stdin, FILE *sys
 
     /* We got an EOF, return a empty string. */
     if (p == NULL) {
-        p = PyMem_Malloc(1);
+        p = malloc(1);
         if (p != NULL)
             *p = '\0';
         RESTORE_LOCALE(saved_locale)
@@ -1125,10 +1125,10 @@ call_readline(FILE *sys_stdin, FILE *sys
         if (strcmp(p, line))
             add_history(p);
     }
-    /* Copy the malloc'ed buffer into a PyMem_Malloc'ed one and
+    /* Copy the malloc'ed buffer into a malloc'ed one and
        release the original. */
     q = p;
-    p = PyMem_Malloc(n+2);
+    p = malloc(n+2);
     if (p != NULL) {
         strncpy(p, q, n);
         p[n] = '\n';
diff -r 464e8fd7300d Parser/myreadline.c
--- a/Parser/myreadline.c	Thu Jun 13 10:08:00 2013 +0300
+++ b/Parser/myreadline.c	Thu Jun 13 23:10:45 2013 +0200
@@ -114,7 +114,7 @@ PyOS_StdioReadline(FILE *sys_stdin, FILE
     size_t n;
     char *p;
     n = 100;
-    if ((p = (char *)PyMem_MALLOC(n)) == NULL)
+    if ((p = (char *)malloc(n)) == NULL)
         return NULL;
     fflush(sys_stdout);
     if (prompt)
@@ -124,7 +124,7 @@ PyOS_StdioReadline(FILE *sys_stdin, FILE
     case 0: /* Normal case */
         break;
     case 1: /* Interrupt */
-        PyMem_FREE(p);
+        free(p);
         return NULL;
     case -1: /* EOF */
     case -2: /* Error */
@@ -135,7 +135,7 @@ PyOS_StdioReadline(FILE *sys_stdin, FILE
     n = strlen(p);
     while (n > 0 && p[n-1] != '\n') {
         size_t incr = n+2;
-        p = (char *)PyMem_REALLOC(p, n + incr);
+        p = (char *)realloc(p, n + incr);
         if (p == NULL)
             return NULL;
         if (incr > INT_MAX) {
@@ -145,14 +145,16 @@ PyOS_StdioReadline(FILE *sys_stdin, FILE
             break;
         n += strlen(p+n);
     }
-    return (char *)PyMem_REALLOC(p, n+1);
+    return (char *)realloc(p, n+1);
 }
 
 
 /* By initializing this function pointer, systems embedding Python can
    override the readline function.
 
-   Note: Python expects in return a buffer allocated with PyMem_Malloc. */
+   The GIL is not hold when PyOS_ReadlineFunctionPointer is called, so
+   PyMem_Malloc() cannot be used. Python expects in return a buffer allocated
+   with malloc(). */
 
 char *(*PyOS_ReadlineFunctionPointer)(FILE *, FILE *, char *);
 
@@ -163,6 +165,8 @@ char *
 PyOS_Readline(FILE *sys_stdin, FILE *sys_stdout, char *prompt)
 {
     char *rv;
+    char *res;
+    size_t len;
 
     if (_PyOS_ReadlineTState == PyThreadState_GET()) {
         PyErr_SetString(PyExc_RuntimeError,
@@ -207,7 +211,18 @@ PyOS_Readline(FILE *sys_stdin, FILE *sys
     PyThread_release_lock(_PyOS_ReadlineLock);
 #endif
 
+    if (rv != NULL) {
+        len = strlen(rv);
+        res = PyMem_Malloc(len + 1);
+        if (res != NULL)
+            memcpy(res, rv, len + 1);
+        free(rv);
+    }
+    else {
+        res = NULL;
+    }
+
     _PyOS_ReadlineTState = NULL;
 
-    return rv;
+    return res;
 }