diff --git a/reVX/hybrid_stats/hybrid_stats.py b/reVX/hybrid_stats/hybrid_stats.py
index 39a8e8849..2fefe93ba 100644
--- a/reVX/hybrid_stats/hybrid_stats.py
+++ b/reVX/hybrid_stats/hybrid_stats.py
@@ -1495,6 +1495,7 @@ def _compute_coefficients(cls, solar_data, wind_data, solar_cap=None,
                                         ['stability'])
         out_stats = {}
         for grp_name, mix_grp in mix:
+            grp_name = grp_name[0] if len(grp_name) == 1 else grp_name
             col = cols_map['stability'][grp_name]
             ref_grp = ref.get_group(grp_name)
             msg = ('mixed and reference data shapes do not match! {} != {}'