diff --git a/tupak/gw/detector.py b/tupak/gw/detector.py
index e2a8244643076cb1f9b0f4bc1ff6550a36bc183e..79964ffc4d453209ac717c57308b4090c1893e2f 100644
--- a/tupak/gw/detector.py
+++ b/tupak/gw/detector.py
@@ -661,7 +661,7 @@ class PowerSpectralDensity:
             self.frequencies = psd.frequencies
             self.power_spectral_density = psd.value
             self.amplitude_spectral_density = self.power_spectral_density ** 0.5
-            self.interpolate_power_spectral_density()
+            self._interpolate_power_spectral_density()
         elif frequencies is not None:
             if asd_array is not None:
                 self._set_from_amplitude_spectral_density(frequencies, asd_array)
@@ -709,15 +709,15 @@ class PowerSpectralDensity:
         self.frequencies = frequencies
         self.amplitude_spectral_density = amplitude_spectral_density
         self.power_spectral_density = self.amplitude_spectral_density ** 2
-        self.interpolate_power_spectral_density()
+        self._interpolate_power_spectral_density()
 
     def _set_from_power_spectral_density(self, frequencies, power_spectral_density):
         self.frequencies = frequencies
         self.power_spectral_density = power_spectral_density
         self.amplitude_spectral_density = self.power_spectral_density ** 0.5
-        self.interpolate_power_spectral_density()
+        self._interpolate_power_spectral_density()
 
-    def interpolate_power_spectral_density(self):
+    def _interpolate_power_spectral_density(self):
         """Interpolate the loaded PSD so it can be resampled for arbitrary frequency arrays."""
         self.power_spectral_density_interpolated = interp1d(self.frequencies, self.power_spectral_density,
                                                             bounds_error=False,