diff --git a/src/Makefile b/src/Makefile
index 128de05..47e136d 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -45,6 +45,7 @@ TESTS := t_benchmark.o \
 	 t_bitreader.o \
 	 t_bitwriter.o \
 	 t_parser.o \
+	 t_misc.o \
 	 test_suite.o
 
 OUTPUTS := libhammer.a \
diff --git a/src/backends/packrat.c b/src/backends/packrat.c
index d05129d..cc2a9db 100644
--- a/src/backends/packrat.c
+++ b/src/backends/packrat.c
@@ -77,14 +77,18 @@ HParserCacheValue* recall(HParserCacheKey *k, HParseState *state) {
 void setupLR(const HParser *p, HParseState *state, HLeftRec *rec_detect) {
   if (!rec_detect->head) {
     HRecursionHead *some = a_new(HRecursionHead, 1);
-    some->head_parser = p; some->involved_set = NULL; some->eval_set = NULL;
+    some->head_parser = p;
+    some->involved_set = h_slist_new(state->arena);
+    some->eval_set = NULL;
     rec_detect->head = some;
   }
   assert(state->lr_stack->head != NULL);
-  HLeftRec *lr = state->lr_stack->head->elem;
-  while (lr && lr->rule != p) {
+  HSlistNode *head = state->lr_stack->head;
+  HLeftRec *lr;
+  while (head && (lr = head->elem)->rule != p) {
     lr->head = rec_detect->head;
     h_slist_push(lr->head->involved_set, (void*)lr->rule);
+    head = head->next;
   }
 }
 
@@ -101,7 +105,7 @@ HParseResult* grow(HParserCacheKey *k, HParseState *state, HRecursionHead *head)
   HParseResult *old_res = old_cached->right->result;
   
   // reset the eval_set of the head of the recursion at each beginning of growth
-  head->eval_set = head->involved_set;
+  head->eval_set = h_slist_copy(head->involved_set);
   HParseResult *tmp_res = perform_lowlevel_parse(state, k->parser);
 
   if (tmp_res) {
diff --git a/src/datastructures.c b/src/datastructures.c
index b1e4f75..3d94804 100644
--- a/src/datastructures.c
+++ b/src/datastructures.c
@@ -41,6 +41,26 @@ HSlist* h_slist_new(HArena *arena) {
   return ret;
 }
 
+HSlist* h_slist_copy(HSlist *slist) {
+  HSlist *ret = h_slist_new(slist->arena);
+  HSlistNode *head = slist->head;
+  HSlistNode *tail;
+  if (head != NULL) {
+    h_slist_push(ret, head->elem);
+    tail = ret->head;
+    head = head->next;
+  }
+  while (head != NULL) {
+    // append head item to tail in a new node
+    HSlistNode *node = h_arena_malloc(slist->arena, sizeof(HSlistNode));
+    node->elem = head->elem;
+    node->next = NULL;
+    tail = tail->next = node;
+    head = head->next;
+  }
+  return ret;
+}
+
 void* h_slist_pop(HSlist *slist) {
   HSlistNode *head = slist->head;
   if (!head)
diff --git a/src/hammer.h b/src/hammer.h
index 0791769..5a0c625 100644
--- a/src/hammer.h
+++ b/src/hammer.h
@@ -43,9 +43,8 @@ typedef enum HTokenType_ {
   TT_SINT,
   TT_UINT,
   TT_SEQUENCE,
-  TT_USER = 64,
   TT_ERR,
-  TT_MAX
+  TT_USER = 64
 } HTokenType;
 
 typedef struct HCountedArray_ {
diff --git a/src/internal.h b/src/internal.h
index 67ecb22..0dcf857 100644
--- a/src/internal.h
+++ b/src/internal.h
@@ -209,6 +209,7 @@ HCountedArray *h_carray_new(HArena * arena);
 void h_carray_append(HCountedArray *array, void* item);
 
 HSlist* h_slist_new(HArena *arena);
+HSlist* h_slist_copy(HSlist *slist);
 void* h_slist_pop(HSlist *slist);
 void h_slist_push(HSlist *slist, void* item);
 bool h_slist_find(HSlist *slist, const void* item);
diff --git a/src/t_misc.c b/src/t_misc.c
new file mode 100644
index 0000000..5c08a2e
--- /dev/null
+++ b/src/t_misc.c
@@ -0,0 +1,16 @@
+#include <glib.h>
+#include "test_suite.h"
+#include "hammer.h"
+
+static void test_tt_user(void) {
+  g_check_cmpint(TT_USER, >, TT_NONE);
+  g_check_cmpint(TT_USER, >, TT_BYTES);
+  g_check_cmpint(TT_USER, >, TT_SINT);
+  g_check_cmpint(TT_USER, >, TT_UINT);
+  g_check_cmpint(TT_USER, >, TT_SEQUENCE);
+  g_check_cmpint(TT_USER, >, TT_ERR);
+}
+
+void register_misc_tests(void) {
+  g_test_add_func("/core/misc/tt_user", test_tt_user);
+}
diff --git a/src/t_parser.c b/src/t_parser.c
index b1f9b63..daca1a3 100644
--- a/src/t_parser.c
+++ b/src/t_parser.c
@@ -365,6 +365,17 @@ static void test_not(void) {
   g_check_parse_ok(not_2, "a++b", 4, "(u0x61 <2b.2b> u0x62)");
 }
 
+static void test_leftrec(void) {
+  const HParser *a_ = h_ch('a');
+
+  HParser *lr_ = h_indirect();
+  h_bind_indirect(lr_, h_choice(h_sequence(lr_, a_, NULL), a_, NULL));
+
+  g_check_parse_ok(lr_, "a", 1, "u0x61");
+  g_check_parse_ok(lr_, "aa", 2, "(u0x61 u0x61)");
+  g_check_parse_ok(lr_, "aaa", 3, "((u0x61 u0x61) u0x61)");
+}
+
 void register_parser_tests(void) {
   g_test_add_func("/core/parser/token", test_token);
   g_test_add_func("/core/parser/ch", test_ch);
@@ -406,4 +417,5 @@ void register_parser_tests(void) {
   g_test_add_func("/core/parser/and", test_and);
   g_test_add_func("/core/parser/not", test_not);
   g_test_add_func("/core/parser/ignore", test_ignore);
+  g_test_add_func("/core/parser/leftrec", test_leftrec);
 }
diff --git a/src/test_suite.c b/src/test_suite.c
index 8d2913a..e01d020 100644
--- a/src/test_suite.c
+++ b/src/test_suite.c
@@ -22,6 +22,7 @@
 extern void register_bitreader_tests();
 extern void register_bitwriter_tests();
 extern void register_parser_tests();
+extern void register_misc_tests();
 extern void register_benchmark_tests();
 
 int main(int argc, char** argv) {
@@ -31,6 +32,7 @@ int main(int argc, char** argv) {
   register_bitreader_tests();
   register_bitwriter_tests();
   register_parser_tests();
+  register_misc_tests();
   register_benchmark_tests();
 
   g_test_run();