diff --git a/gwsumm/data/coherence.py b/gwsumm/data/coherence.py
index a6144310..f3a2a4dc 100644
--- a/gwsumm/data/coherence.py
+++ b/gwsumm/data/coherence.py
@@ -291,8 +291,8 @@ def _get_coherence_spectrogram(channel_pair, segments, config=None,
                 globalv.SPECTROGRAMS[key].coalesce()
             else:
                 warnings.warn('NaN values found in the spectrogram.'
-                                         ' Spectrogram will not be appended to'
-                                         ' global memory value')
+                              ' Spectrogram will not be appended to'
+                              ' global memory value')
 
     if not return_:
         return