diff --git a/lib/server.js b/lib/server.js
index 90bd598..f04b9c5 100644
--- a/lib/server.js
+++ b/lib/server.js
@@ -1202,6 +1202,12 @@ WalletService.prototype.signTx = function(opts, cb) {
     }, function(err, txp) {
       if (err) return cb(err);
 
+      if (!self.clientVersion || /^bw.-0\.0\./.test(self.clientVersion)) {
+        if (!_.startsWith(txp.version, '1.')) {
+          return cb(new ClientError(Errors.codes.UPGRADE_NEEDED, 'This spend proposal was created using a newer version of the client app'));
+        }
+      }
+
       var action = _.find(txp.actions, {
         copayerId: self.copayerId
       });
@@ -1366,14 +1372,6 @@ WalletService.prototype.getPendingTxs = function(opts, cb) {
   self.storage.fetchPendingTxs(self.walletId, function(err, txps) {
     if (err) return cb(err);
 
-    if (!self.clientVersion || /^bw.-0\.0\./.test(self.clientVersion)) {
-      var allLegacy = _.all(txps, function(txp) {
-        return _.startsWith(txp.version, '1.');
-      });
-
-      if (!allLegacy) return cb(new ClientError(Errors.codes.UPGRADE_NEEDED, 'Some spend proposals were created using a newer version of the client app'));
-    }
-
     _.each(txps, function(txp) {
       txp.deleteLockTime = self.getRemainingDeleteLockTime(txp);
     });
diff --git a/test/integration/server.js b/test/integration/server.js
index cb19bf0..0584af0 100644
--- a/test/integration/server.js
+++ b/test/integration/server.js
@@ -4286,7 +4286,8 @@ describe('Wallet service', function() {
           });
         });
       });
-      it('should return error when fetching new txps from legacy (bwc-0.0.*) client', function(done) {
+
+      it('should not return error when fetching new txps from legacy (bwc-0.0.*) client', function(done) {
         helpers.stubUtxos(server, wallet, [100, 200], function() {
           var txOpts = helpers.createSimpleProposalOpts('18PzpUFkFZE8zKWUPvfykkTxmB9oMR8qP7', 80, 'some message', TestData.copayers[0].privKey_1H_0);
           server.createTx(txOpts, function(err, tx) {
@@ -4301,12 +4302,41 @@ describe('Wallet service', function() {
               signature: 'dummy',
               clientVersion: 'bwc-0.0.40',
             }, function(err, server) {
+              verifyStub.restore();
               should.not.exist(err);
               should.exist(server);
-              verifyStub.restore();
               server.getPendingTxs({}, function(err, txps) {
+                should.not.exist(err);
+                should.exist(txps);
+                done();
+              });
+            });
+          });
+        });
+      });
+      it('should fail to sign tx from legacy (bwc-0.0.*) client', function(done) {
+        helpers.stubUtxos(server, wallet, [100, 200], function() {
+          var txOpts = helpers.createSimpleProposalOpts('18PzpUFkFZE8zKWUPvfykkTxmB9oMR8qP7', 80, 'some message', TestData.copayers[0].privKey_1H_0);
+          server.createTx(txOpts, function(err, tx) {
+            should.not.exist(err);
+            should.exist(tx);
+            _.startsWith(tx.version, '1.').should.be.false;
+
+            var verifyStub = sinon.stub(WalletService.prototype, '_verifySignature');
+            verifyStub.returns(true);
+            WalletService.getInstanceWithAuth({
+              copayerId: wallet.copayers[0].id,
+              message: 'dummy',
+              signature: 'dummy',
+              clientVersion: 'bwc-0.0.40',
+            }, function(err, server) {
+              var signatures = helpers.clientSign(tx, TestData.copayers[0].xPrivKey);
+              server.signTx({
+                txProposalId: tx.id,
+                signatures: signatures,
+              }, function(err) {
+                verifyStub.restore();
                 should.exist(err);
-                should.not.exist(txps);
                 err.code.should.equal('UPGRADE_NEEDED');
                 err.message.should.contain('newer version');
                 done();