diff --git a/scripts/update_api.py b/scripts/update_api.py
index 43903e92c..8c6275c56 100755
--- a/scripts/update_api.py
+++ b/scripts/update_api.py
@@ -91,7 +91,7 @@ Type2Dotnet = { VOID : 'void', VOID_PTR : 'IntPtr', INT : 'int', UINT : 'uint',
 
 
 # Mapping to ML types
-Type2ML = { VOID : 'unit', VOID_PTR : 'ptr', INT : 'int', UINT : 'int', INT64 : 'int', UINT64 : 'int', DOUBLE : 'float',
+Type2ML = { VOID : 'unit', VOID_PTR : 'ptr', INT : 'int', UINT : 'int', INT64 : 'int64', UINT64 : 'int64', DOUBLE : 'float',
             FLOAT : 'float', STRING : 'string', STRING_PTR : 'char**',
             BOOL : 'bool', SYMBOL : 'z3_symbol', PRINT_MODE : 'int', ERROR_CODE : 'int', CHAR : 'char', CHAR_PTR : 'string', LBOOL : 'int' }
 
@@ -254,8 +254,10 @@ def param2pystr(p):
 def param2ml(p):
     k = param_kind(p)
     if k == OUT:
-        if param_type(p) == INT or param_type(p) == UINT or param_type(p) == BOOL or param_type(p) == INT64 or param_type(p) == UINT64:
+        if param_type(p) == INT or param_type(p) == UINT or param_type(p) == BOOL:
             return "int"
+        elif param_type(p) == INT64 or param_type(p) == UINT64:
+            return "int64"
         elif param_type(p) == STRING:
             return "string"
         else:
@@ -1252,9 +1254,9 @@ def ml_unwrap(t, ts, s):
     elif t == UINT:
         return '(' + ts + ') Unsigned_int_val(' + s + ')'
     elif t == INT64:
-        return '(' + ts + ') Long_val(' + s + ')'
+        return '(' + ts + ') Int64_val(' + s + ')'
     elif t == UINT64:
-        return '(' + ts + ') Unsigned_long_val(' + s + ')'
+        return '(' + ts + ') Int64_val(' + s + ')'
     elif t == DOUBLE:
         return '(' + ts + ') Double_val(' + s + ')'
     elif ml_has_plus_type(ts):
@@ -1271,7 +1273,7 @@ def ml_set_wrap(t, d, n):
     elif t == INT or t == UINT or t == PRINT_MODE or t == ERROR_CODE or t == LBOOL:
         return d + ' = Val_int(' + n + ');'
     elif t == INT64 or t == UINT64:
-        return d + ' = Val_long(' + n + ');'
+        return d + ' = caml_copy_int64(' + n + ');'
     elif t == DOUBLE:
         return d + '= caml_copy_double(' + n + ');'
     elif t == STRING:
diff --git a/src/api/ml/z3.mli b/src/api/ml/z3.mli
index 74320dd72..a7c629018 100644
--- a/src/api/ml/z3.mli
+++ b/src/api/ml/z3.mli
@@ -927,10 +927,10 @@ end
 module FiniteDomain :
 sig
   (** Create a new finite domain sort. *)
-  val mk_sort : context -> Symbol.symbol -> int -> Sort.sort
+  val mk_sort : context -> Symbol.symbol -> int64 -> Sort.sort
 
   (** Create a new finite domain sort. *)
-  val mk_sort_s : context -> string -> int -> Sort.sort
+  val mk_sort_s : context -> string -> int64 -> Sort.sort
 
   (** Indicates whether the term is of an array sort. *)
   val is_finite_domain : Expr.expr -> bool
@@ -939,7 +939,7 @@ sig
   val is_lt : Expr.expr -> bool
 
   (** The size of the finite domain sort. *)
-  val get_size : Sort.sort -> int
+  val get_size : Sort.sort -> int64
 end
 
 
@@ -2078,7 +2078,7 @@ sig
   val mk_numeral_i : context -> int -> Sort.sort -> Expr.expr
 
   (** Create a numeral of FloatingPoint sort from a sign bit and two integers. *)
-  val mk_numeral_i_u : context -> bool -> int -> int -> Sort.sort -> Expr.expr
+  val mk_numeral_i_u : context -> bool -> int64 -> int64 -> Sort.sort -> Expr.expr
 
   (** Create a numeral of FloatingPoint sort from a string *)
   val mk_numeral_s : context -> string -> Sort.sort -> Expr.expr
@@ -2303,7 +2303,7 @@ sig
   val get_numeral_exponent_string : context -> Expr.expr -> bool -> string
 
   (** Return the exponent value of a floating-point numeral as a signed integer *)
-  val get_numeral_exponent_int : context -> Expr.expr -> bool -> bool * int
+  val get_numeral_exponent_int : context -> Expr.expr -> bool -> bool * int64
 
   (** Return the exponent of a floating-point numeral as a bit-vector expression. 
       Remark: NaN's do not have a bit-vector exponent, so they are invalid arguments. *)
@@ -2320,7 +2320,7 @@ sig
       Remark: This function extracts the significand bits, without the
       hidden bit or normalization. Throws an exception if the
       significand does not fit into an int. *)
-  val get_numeral_significand_uint : context -> Expr.expr -> bool * int
+  val get_numeral_significand_uint : context -> Expr.expr -> bool * int64
 
   (** Indicates whether a floating-point numeral is a NaN. *)
   val is_numeral_nan : context -> Expr.expr -> bool
diff --git a/src/smt/smt_internalizer.cpp b/src/smt/smt_internalizer.cpp
index 451136351..092bc0127 100644
--- a/src/smt/smt_internalizer.cpp
+++ b/src/smt/smt_internalizer.cpp
@@ -1429,7 +1429,10 @@ namespace smt {
                 inc_ref(l2);
                 m_watches[(~l1).index()].insert_literal(l2);
                 m_watches[(~l2).index()].insert_literal(l1);
-                if (get_assignment(l2) == l_false) {
+                if (get_assignment(l1) == l_false) {
+                    assign(l2, b_justification(~l1));
+                }
+                else if (get_assignment(l2) == l_false) {
                     assign(l1, b_justification(~l2));
                 }
                 m_clause_proof.add(l1, l2, k, j);
diff --git a/src/solver/parallel_tactic.cpp b/src/solver/parallel_tactic.cpp
index c79f52084..1d24ed1e6 100644
--- a/src/solver/parallel_tactic.cpp
+++ b/src/solver/parallel_tactic.cpp
@@ -113,9 +113,9 @@ class parallel_tactic : public tactic {
 
         void shutdown() {
             if (!m_shutdown) {
+                std::lock_guard<std::mutex> lock(m_mutex);
                 m_shutdown = true;
                 m_cond.notify_all();
-                std::lock_guard<std::mutex> lock(m_mutex);
                 for (solver_state* st : m_active) {
                     st->m().limit().cancel();
                 }
@@ -147,7 +147,9 @@ class parallel_tactic : public tactic {
                 }
                 {
                     std::unique_lock<std::mutex> lock(m_mutex);
-                    m_cond.wait(lock);
+                    if (!m_shutdown) {
+                        m_cond.wait(lock);
+                    }
                 }
                 dec_wait();
             }