diff --git a/azure-pipelines/simple_test_framework.yml b/azure-pipelines/simple_test_framework.yml
index 3e22d4e28b4..1e3b323e7dc 100644
--- a/azure-pipelines/simple_test_framework.yml
+++ b/azure-pipelines/simple_test_framework.yml
@@ -59,7 +59,7 @@ jobs:
         source activate tardis
         conda install -y pytest-cov
         pip install git+https://github.com/tonybaloney/pytest-azurepipelines.git
-        pytest tardis --tardis-refdata=$(ref.data.home) --cov=tardis --cov-report=xml --cov-report=html
+        pytest -s tardis/tests/test_tardis_full_formal_integral.py --tardis-refdata=$(ref.data.home) --cov=tardis --cov-report=xml --cov-report=html
     displayName: 'TARDIS test'
 
 
diff --git a/tardis/montecarlo/base.py b/tardis/montecarlo/base.py
index 5a116cd3be4..ddd101998e9 100644
--- a/tardis/montecarlo/base.py
+++ b/tardis/montecarlo/base.py
@@ -145,9 +145,11 @@ def spectrum_virtual(self):
 
     @property
     def spectrum_integrated(self):
-        if self._spectrum_integrated is None:
-            self._spectrum_integrated = self.integrator.calculate_spectrum(
-                self.spectrum_frequency[:-1], **self.integrator_settings)
+        self._spectrum_integrated = self.integrator.calculate_spectrum(
+            self.spectrum_frequency[:-1], **self.integrator_settings)
+        # if self._spectrum_integrated is None:
+        #     self._spectrum_integrated = self.integrator.calculate_spectrum(
+        #         self.spectrum_frequency[:-1], **self.integrator_settings)
         return self._spectrum_integrated
 
     @property
diff --git a/tardis/montecarlo/src/integrator.c b/tardis/montecarlo/src/integrator.c
index 3d7f5bf6c86..c885257d458 100644
--- a/tardis/montecarlo/src/integrator.c
+++ b/tardis/montecarlo/src/integrator.c
@@ -1,5 +1,6 @@
 #define _USE_MATH_DEFINES
 
+#include <inttypes.h>
 #include <string.h>
 #include <assert.h>
 #include <stdio.h>
@@ -210,7 +211,7 @@ _formal_integral(
       for (i = 0; i < size_tau; ++i) {
           exp_tau[i] = exp( -storage->line_lists_tau_sobolevs_i[i]);
       }
-      calculate_p_values(storage->r_outer_i[storage->no_of_shells_i - 1], N, pp);
+      calculate_p_values(R_max, N, pp);
       // Done with the initialization
 
       // Loop over wavelengths in spectrum
@@ -335,7 +336,8 @@ _formal_integral(
           }
         }
       // Free everything allocated on heap
+      free(exp_tau);
       printf("\n");
     }
   return L;
-}
+}
\ No newline at end of file
diff --git a/tardis/tests/test_tardis_full_formal_integral.py b/tardis/tests/test_tardis_full_formal_integral.py
index acd150487d2..d3de68501c4 100644
--- a/tardis/tests/test_tardis_full_formal_integral.py
+++ b/tardis/tests/test_tardis_full_formal_integral.py
@@ -7,7 +7,7 @@
 
 from tardis.simulation.base import Simulation
 from tardis.io.config_reader import Configuration
-
+import astropy
 
 config_line_modes = ['downbranch', 'macroatom']
 interpolate_shells = [-1, 30]
@@ -24,6 +24,7 @@ def base_config(request):
     config["montecarlo"]["no_of_virtual_packets"] = 0
     config["spectrum"]["method"] = "integrated"
     config["spectrum"]["integrated"]["points"] = 200
+    print("config", config)
 
     return config
 
@@ -92,6 +93,7 @@ def test_spectrum_integrated(self, runner, refdata):
         luminosity = u.Quantity(
                 refdata('spectrum_integrated/luminosity'), 'erg /s')
 
+        print("actual, desired: ", luminosity, runner.spectrum_integrated.luminosity)
         assert_quantity_allclose(
             runner.spectrum_integrated.luminosity,
             luminosity)
diff --git a/tardis_env3.yml b/tardis_env3.yml
index 28d807d1ac0..37cc132dc58 100644
--- a/tardis_env3.yml
+++ b/tardis_env3.yml
@@ -9,7 +9,7 @@ dependencies:
 - numpy=1.15
 - scipy=1.1
 - pandas=0.24
-- astropy=3
+- astropy=3.2.1
 
 - numba=0.43
 - numexpr