diff --git a/src/CHANGELOG b/src/CHANGELOG
index 02a47ca42..a8e29d59c 100755
--- a/src/CHANGELOG
+++ b/src/CHANGELOG
@@ -53,6 +53,11 @@ ECL 13.4.1
 - New functions RATIOP, {SINGLE,SHORT,DOUBLE,LONG}-FLOAT-P help avoid consing
   in TYPEP
 
+- HASH-TABLE-COUNT did not work with weak hashes: it did not update the count
+  of live cells (Note, however, that this function is by definition not
+  reliable, just a hint, since a garbage collection may happen while the count
+  is being computed)
+
 * CLOS:
 
 - Added built in classes FIXNUM and BIGNUM.
diff --git a/src/c/hash.d b/src/c/hash.d
index 51e133643..bb68640a6 100644
--- a/src/c/hash.d
+++ b/src/c/hash.d
@@ -970,11 +970,33 @@ cl_hash_table_size(cl_object ht)
 	@(return ecl_make_fixnum(ht->hash.size))
 }
 
+cl_index
+ecl_hash_table_count(cl_object ht)
+{
+	if (ht->hash.weak == ecl_htt_not_weak) {
+		return ht->hash.entries;
+	} else if (ht->hash.size) {
+		cl_index i, j;
+		for (i = j = 0; i < ht->hash.size; i++) {
+			struct ecl_hashtable_entry output =
+				copy_entry(ht->hash.data + i, ht);
+			if (output.key != OBJNULL) {
+				if (++j == ht->hash.size)
+					break;
+			}
+		}
+		return ht->hash.entries = j;
+	} else {
+		return 0;
+	}
+}
+
+
 cl_object
 cl_hash_table_count(cl_object ht)
 {
 	assert_type_hash_table(@[hash-table-count], 1, ht);
-	@(return (ecl_make_fixnum(ht->hash.entries)))
+	@(return (ecl_make_fixnum(ecl_hash_table_count(ht))))
 }
 
 static cl_object
diff --git a/src/cmp/sysfun.lsp b/src/cmp/sysfun.lsp
index 0e486c232..481bab188 100644
--- a/src/cmp/sysfun.lsp
+++ b/src/cmp/sysfun.lsp
@@ -284,6 +284,7 @@
 
 (def-inline gethash :always (t t t) t "ecl_gethash_safe(#0,#1,#2)" :multiple-values nil)
 (def-inline gethash :always (t t) t "ecl_gethash_safe(#0,#1,ECL_NIL)" :multiple-values nil)
+(def-inline hash-table-count :unsafe (hash-table) ext:array-index "ecl_hash_table_count(#0)")
 
 ;; file list.d
 
diff --git a/src/h/external.h b/src/h/external.h
index 4670e10a1..e3dee7768 100755
--- a/src/h/external.h
+++ b/src/h/external.h
@@ -817,6 +817,7 @@ extern ECL_API cl_object ecl_gethash(cl_object key, cl_object hash);
 extern ECL_API cl_object ecl_gethash_safe(cl_object key, cl_object hash, cl_object def);
 extern ECL_API bool ecl_remhash(cl_object key, cl_object hash);
 extern ECL_API cl_object _ecl_sethash(cl_object key, cl_object hashtable, cl_object value);
+extern ECL_API cl_index ecl_hash_table_count(cl_object hash);
 
 /* instance.c */