diff --git a/m-array.h b/m-array.h
index 0353e468..939ab571 100644
--- a/m-array.h
+++ b/m-array.h
@@ -596,12 +596,15 @@
     M_C3(array_, name,_clean)(array);                                   \
     char c = fgetc(file);                                               \
     if (c != '[') return false;                                         \
+    c = fgetc(file);                                                    \
+    if (c == ']') return true;                                          \
+    ungetc(c, file);                                                    \
     type item;                                                          \
     M_GET_INIT oplist (item);                                           \
     do {                                                                \
       bool b = M_GET_IN_STR oplist (item, file);                        \
       c = fgetc(file);                                                  \
-      if (!b) { /* How to push back char in stream ? */ break; }        \
+      if (!b) { break; }                                                \
       M_C3(array_, name, _push_back)(array, item);                      \
     } while (c == M_GET_SEPARATOR oplist && !feof(file) && !ferror(file)); \
     M_GET_CLEAR oplist (item);                                          \
diff --git a/m-bitset.h b/m-bitset.h
index 819f7d6f..6256386c 100644
--- a/m-bitset.h
+++ b/m-bitset.h
@@ -429,7 +429,7 @@ bitset_in_str(bitset_t set, FILE *file)
   if (c != '[') return false;
   c = fgetc(file);
   do {
-    if (c != '0' && c != '1') return false;
+    if (c != '0' && c != '1') break;
     bool b = (c == '1');
     bitset_push_back (set, b);
     c = fgetc(file);
diff --git a/m-dict.h b/m-dict.h
index 31ebcb1e..99841c1e 100644
--- a/m-dict.h
+++ b/m-dict.h
@@ -403,6 +403,9 @@
     M_C3(dict_, name, _clean)(dict);                                    \
     char c = fgetc(file);                                               \
     if (c != '{') return false;                                         \
+    c = fgetc(file);                                                    \
+    if (c == '}') return true;                                          \
+    ungetc(c, file);                                                    \
     key_type key;                                                       \
     value_type value;                                                   \
     M_GET_INIT key_oplist (key);                                        \
diff --git a/m-list.h b/m-list.h
index 9a956ad0..fc1e7fa2 100644
--- a/m-list.h
+++ b/m-list.h
@@ -511,6 +511,9 @@
     M_C3(list_, name,_clean)(list);                                     \
     char c = fgetc(file);                                               \
     if (c != '[') return false;                                         \
+    c = fgetc(file);                                                    \
+    if (c == ']') return true;                                          \
+    ungetc(c, file);                                                    \
     type item;                                                          \
     M_GET_INIT oplist (item);                                           \
     do {                                                                \
diff --git a/m-rbtree.h b/m-rbtree.h
index 9dde9a84..ea33f18e 100644
--- a/m-rbtree.h
+++ b/m-rbtree.h
@@ -852,6 +852,9 @@ typedef enum {
     M_C3(rbtree_, name,_clean)(rbtree);                                 \
     char c = fgetc(file);                                               \
     if (c != '[') return false;                                         \
+    c = fgetc(file);                                                    \
+    if (c == ']') return true;                                          \
+    ungetc(c, file);                                                    \
     type item;                                                          \
     M_GET_INIT oplist (item);                                           \
     do {                                                                \
diff --git a/tests/test-marray.c b/tests/test-marray.c
index 380dac9f..8d1bfb67 100644
--- a/tests/test-marray.c
+++ b/tests/test-marray.c
@@ -163,7 +163,7 @@ static void test_mpz(void)
   f = fopen ("a.dat", "rt");
   if (!f) abort();
   bool b = array_mpz_in_str (array2, f);
-  //assert (b == true); // The test fail. How to fix?
+  assert (b == true); // The test fail. How to fix?
   assert (array_mpz_equal_p (array1, array2));
   fclose(f);