diff --git a/src/nft/operations.cc b/src/nft/operations.cc
index 58c54371a..ecedc3caf 100644
--- a/src/nft/operations.cc
+++ b/src/nft/operations.cc
@@ -1271,7 +1271,7 @@ bool Nft::is_in_lang_by_levels(const std::vector<Word>& level_words, const bool
                     if (level == 0 && level_target == 0) {
                         for (Level level_loop{ level }; level_loop < levels.num_of_levels; ++level_loop) {
                             if (next_words_its[level_loop] == track_words_ends[level_loop] ||
-                                not symbols_match(*word_symbol_it, *next_words_its[level_loop])) {
+                                not symbols_match(symbol_post_it->symbol, *next_words_its[level_loop])) {
                                 jump_failed = true;
                                 break;
                             }
@@ -1281,7 +1281,7 @@ bool Nft::is_in_lang_by_levels(const std::vector<Word>& level_words, const bool
                         for (Level level_loop{ level }; level_loop != level_target;
                              level_loop = levels.next_level_after(level_loop)) {
                             if (next_words_its[level_loop] == track_words_ends[level_loop] ||
-                                not symbols_match(*word_symbol_it, *next_words_its[level_loop])) {
+                                not symbols_match(symbol_post_it->symbol, *next_words_its[level_loop])) {
                                 jump_failed = true;
                                 break;
                             }
diff --git a/tests/nft/nft.cc b/tests/nft/nft.cc
index 9f2fd5e9a..8edc9eb4f 100644
--- a/tests/nft/nft.cc
+++ b/tests/nft/nft.cc
@@ -3418,6 +3418,30 @@ TEST_CASE("mata::nft:: create simple automata") {
     CHECK(!nft.is_in_lang({ 3 }));
 }
 
+TEST_CASE("ISSUE #613 - mata::nft::nft::is_in_lang()") {
+    SECTION("DONT_CARE jump") {
+        Nft nft{ builder::create_sigma_star_nft(2) };
+        CHECK(nft.is_in_lang({ 'a', 'b' }));
+        CHECK(nft.is_in_lang({ 'a', 'a' }));
+        CHECK(nft.is_in_lang({ 'b', 'a' }));
+
+        Nft nft3{ builder::create_sigma_star_nft(3) };
+        CHECK(nft3.is_in_lang({ 'a', 'b', 'c' }));
+    }
+
+    SECTION("DONT_CARE in the word") {
+        Nft nft{ Nft::with_levels({ 2, { 0 } }, 1, { 0 }, { 0 }) };
+        nft.delta.add(0, 'x', 0);
+
+        CHECK(nft.is_in_lang({ 'x', 'x' }));
+        CHECK(nft.is_in_lang({ DONT_CARE, 'x' }));
+        CHECK(nft.is_in_lang({ 'x', DONT_CARE }));
+        CHECK(!nft.is_in_lang({ DONT_CARE, 'b' }));
+        CHECK(!nft.is_in_lang({ 'b', DONT_CARE }));
+    }
+}
+
+
 TEST_CASE("mata::nft::print_to_mata()") {
     Nft aut_big{ Nft::with_levels(2, 9) };
     aut_big.initial = { 1, 2 };