diff --git a/Misc/NEWS b/Misc/NEWS
index 09ab65eae9f..ee4bf2b7875 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -44,6 +44,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #5918: Fix a crash in the parser module.
+
 - Issue #8688: Distutils now recalculates MANIFEST everytime.
 
 - Issue #7640: In the new `io` module, fix relative seek() for buffered
diff --git a/Modules/parsermodule.c b/Modules/parsermodule.c
index 0dd69cda1a4..425d97f6bfa 100644
--- a/Modules/parsermodule.c
+++ b/Modules/parsermodule.c
@@ -2092,14 +2092,14 @@ validate_try(node *tree)
         return (res);
     }
     /* try/except statement: skip past except_clause sections */
-    while (res && (TYPE(CHILD(tree, pos)) == except_clause)) {
+    while (res && pos < nch && (TYPE(CHILD(tree, pos)) == except_clause)) {
         res = (validate_except_clause(CHILD(tree, pos))
                && validate_colon(CHILD(tree, pos + 1))
                && validate_suite(CHILD(tree, pos + 2)));
         pos += 3;
     }
     /* skip else clause */
-    if (res && (TYPE(CHILD(tree, pos)) == NAME) &&
+    if (res && pos < nch && (TYPE(CHILD(tree, pos)) == NAME) &&
         (strcmp(STR(CHILD(tree, pos)), "else") == 0)) {
         res = (validate_colon(CHILD(tree, pos + 1))
                && validate_suite(CHILD(tree, pos + 2)));