diff --git a/src/pattern.c b/src/pattern.c
index 228cdf0..28737b1 100644
--- a/src/pattern.c
+++ b/src/pattern.c
@@ -203,6 +203,10 @@ liblex_result _pattern_build_or(pattern_chain** into, int* ids, int pattern_id,
     result = _pattern_chain_create(into, NULL, tail_node);
   }
 
+  if(result == LIBLEX_SUCCESS){
+    (*index)++;
+  }
+
   while (string[*index] && string[*index] != ']' && result == LIBLEX_SUCCESS) {
     char from = '\0';
     char to = '\0';
@@ -248,6 +252,8 @@ liblex_result _pattern_build_or(pattern_chain** into, int* ids, int pattern_id,
       free(tail_node);
     }
     free(*into);
+  } else {
+    (*index)++;
   }
 
   return result;