1 files changed, 3 insertions, 1 deletions
diff --git a/src/subst.c b/src/subst.c
index 6c8bec6..20a6790 100644
--- a/src/subst.c
+++ b/src/subst.c
@@ -6,6 +6,7 @@
 struct l2_subst__item {
   char *name;
   char *value;
+  size_t namelen;
 
   struct l2_subst__item *next;
 };
@@ -46,6 +47,7 @@ int l2_subst_add(l2_subst_t *sp, const char *name, const char *value)
 
   item->name = namedup;
   item->value = valdup;
+  item->namelen = strlen(name);
   item->next = sp->items;
   sp->items = item;
 
@@ -55,7 +57,7 @@ int l2_subst_add(l2_subst_t *sp, const char *name, const char *value)
 const char *l2_subst__find(l2_subst_t *sp, const char *name, size_t len)
 {
   for (struct l2_subst__item *item = sp->items; item; item = item->next) {
-    if (!strncmp(item->name, name, len)) return item->value;
+    if (item->namelen == len && !strncmp(item->name, name, len)) return item->value;
   }
   return NULL;
 }