diff --git a/py/fastspecfit/emline_fit/interface.py b/py/fastspecfit/emline_fit/interface.py
index 9c271fe7..dc6f037f 100644
--- a/py/fastspecfit/emline_fit/interface.py
+++ b/py/fastspecfit/emline_fit/interface.py
@@ -3,6 +3,8 @@
 
 from numba import jit
 
+from fastspecfit.resolution import Resolution
+
 from .params_mapping import ParamsMapping
 from .sparse_rep import EMLineJacobian
 
@@ -330,6 +332,11 @@ def _suppress_negative_fluxes(endpts, M):
                 for j in range(e-s):
                     M[i,j] = np.maximum(M[i,j], 0.)
 
+        if resolution_matrices is None:
+            # create trivial diagonal resolution matrices
+            rm = [ Resolution(np.ones((1, e - s))) for (s, e) in camerapix ]
+            resolution_matrices = tuple(rm)
+
         self.line_models = []
         _build_multimodel_core(line_parameters,
                                obs_bin_centers,
@@ -345,7 +352,6 @@ def _suppress_negative_fluxes(endpts, M):
             _suppress_negative_fluxes(endpts, M)
 
 
-
     def getLine(self, line):
         """
         Return a model for one emission line.
diff --git a/py/fastspecfit/emlines.py b/py/fastspecfit/emlines.py
index 7094d510..02976fc6 100644
--- a/py/fastspecfit/emlines.py
+++ b/py/fastspecfit/emlines.py
@@ -861,7 +861,7 @@ def get_line_profiles(values):
             line_wavelengths = self.line_table['restwave'].value
             return EMLine_MultiLines(
                 parameters, emlinewave, redshift, line_wavelengths,
-                resolution_matrices, camerapix)
+                resolution_matrices=None, camerapix=camerapix) # omit per-camera resolution matrix transformations
 
         values = linemodel['value'].value
         obsamps = linemodel.meta['obsamps']