diff --git a/Misc/NEWS.d/next/Core and Builtins/2018-07-11-11-20-12.bpo-34080.8t7PtO.rst b/Misc/NEWS.d/next/Core and Builtins/2018-07-11-11-20-12.bpo-34080.8t7PtO.rst
new file mode 100644
index 00000000000000..cfc53cca487907
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2018-07-11-11-20-12.bpo-34080.8t7PtO.rst	
@@ -0,0 +1,2 @@
+Fixed a memory leak in the compiler when it raised some uncommon errors
+during tokenizing.
diff --git a/Parser/parsetok.c b/Parser/parsetok.c
index 1f467d63c41e24..33301c47c2f726 100644
--- a/Parser/parsetok.c
+++ b/Parser/parsetok.c
@@ -246,8 +246,6 @@ parsetok(struct tok_state *tok, grammar *g, int start, perrdetail *err_ret,
             else if ((ps->p_flags & CO_FUTURE_BARRY_AS_BDFL) &&
                             strcmp(str, "<>")) {
                 PyObject_FREE(str);
-                err_ret->text = "with Barry as BDFL, use '<>' "
-                                "instead of '!='";
                 err_ret->error = E_SYNTAX;
                 break;
             }
@@ -322,7 +320,10 @@ parsetok(struct tok_state *tok, grammar *g, int start, perrdetail *err_ret,
             assert(tok->cur - tok->buf < INT_MAX);
             err_ret->offset = (int)(tok->cur - tok->buf);
             len = tok->inp - tok->buf;
-            err_ret->text = (char *) PyObject_MALLOC(len + 1);
+            /* make sure that we don't leak memory if text has been
+               set previously */
+            assert(err_ret->text == NULL);
+            err_ret->text = (char *) PyObject_Malloc(len + 1);
             if (err_ret->text != NULL) {
                 if (len > 0)
                     strncpy(err_ret->text, tok->buf, len);
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index bcd1ca931d03d3..73376ec763e376 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -63,7 +63,7 @@ static PyObject *run_mod(mod_ty, PyObject *, PyObject *, PyObject *,
                           PyCompilerFlags *, PyArena *);
 static PyObject *run_pyc_file(FILE *, const char *, PyObject *, PyObject *,
                               PyCompilerFlags *);
-static void err_input(perrdetail *);
+static void err_input(const perrdetail *);
 static void err_free(perrdetail *);
 static int PyRun_InteractiveOneObjectEx(FILE *, PyObject *, PyCompilerFlags *);
 
@@ -1324,12 +1324,14 @@ static void
 err_free(perrdetail *err)
 {
     Py_CLEAR(err->filename);
+    PyObject_Free(err->text);
+    err->text = NULL;
 }
 
 /* Set the error appropriate to the given input error code (see errcode.h) */
 
 static void
-err_input(perrdetail *err)
+err_input(const perrdetail *err)
 {
     PyObject *v, *w, *errtype, *errtext;
     PyObject *msg_obj = NULL;
@@ -1445,10 +1447,6 @@ err_input(perrdetail *err)
     Py_XDECREF(w);
 cleanup:
     Py_XDECREF(msg_obj);
-    if (err->text != NULL) {
-        PyObject_FREE(err->text);
-        err->text = NULL;
-    }
 }