diff --git a/mne/simulation/evoked.py b/mne/simulation/evoked.py
index 0bbf8af4cdc..d984b01d32b 100644
--- a/mne/simulation/evoked.py
+++ b/mne/simulation/evoked.py
@@ -69,8 +69,8 @@ def simulate_evoked(fwd, stc, info, cov, snr=3., tmin=None, tmax=None,
     evoked = apply_forward(fwd, stc, info)
     if snr < np.inf:
         noise = simulate_noise_evoked(evoked, cov, iir_filter, random_state)
-        evoked_noise = add_noise_evoked(evoked, noise, snr,
-                                        tmin=tmin, tmax=tmax)
+        evoked_noise = add_noise_evoked(evoked, noise, snr, tmin=tmin,
+                                        tmax=tmax)
     else:
         evoked_noise = evoked
     return evoked_noise
@@ -111,6 +111,12 @@ def _generate_noise(info, cov, iir_filter, random_state, n_samples, zi=None):
     """Helper to create spatially colored and temporally IIR-filtered noise"""
     from scipy.signal import lfilter
     noise_cov = pick_channels_cov(cov, include=info['ch_names'], exclude=[])
+    if set(info['ch_names']) != set(noise_cov.ch_names):
+        raise ValueError('Evoked and covariance channel names are not '
+                         'identical. Cannot generate the noise matrix. '
+                         'Channels missing in covariance %s.' %
+                         np.setdiff1d(info['ch_names'], noise_cov.ch_names))
+
     rng = check_random_state(random_state)
     c = np.diag(noise_cov.data) if noise_cov['diag'] else noise_cov.data
     mu_channels = np.zeros(len(c))
diff --git a/mne/simulation/tests/test_evoked.py b/mne/simulation/tests/test_evoked.py
index 01be7388142..6f1727556ba 100644
--- a/mne/simulation/tests/test_evoked.py
+++ b/mne/simulation/tests/test_evoked.py
@@ -65,6 +65,7 @@ def test_simulate_evoked():
     stc_bad = stc.copy()
     mv = np.max(fwd['src'][0]['vertno'][fwd['src'][0]['inuse']])
     stc_bad.vertices[0][0] = mv + 1
+
     assert_raises(RuntimeError, simulate_evoked, fwd, stc_bad,
                   evoked_template.info, cov, snr, tmin=0.0, tmax=0.2)
     evoked_1 = simulate_evoked(fwd, stc, evoked_template.info, cov, np.inf,
@@ -82,9 +83,13 @@ def test_simulate_evoked():
                                    iir_filter=None)
     noise = evoked_noise.data - evoked_clean.data
 
-    empirical_snr = 10 * np.log10(np.mean((evoked_clean.data**2).ravel()) /
-                                  np.mean((noise**2).ravel()))
+    empirical_snr = 10 * np.log10(np.mean((evoked_clean.data ** 2).ravel()) /
+                                  np.mean((noise ** 2).ravel()))
 
     assert_almost_equal(snr, empirical_snr, decimal=5)
 
+    cov['names'] = cov.ch_names[:-2]  # Error channels are different.
+    assert_raises(ValueError, simulate_evoked, fwd, stc, evoked_template.info,
+                  cov, snr=3., tmin=None, tmax=None, iir_filter=None)
+
 run_tests_if_main()