diff --git a/tardis/montecarlo/montecarlo_numba/formal_integral.py b/tardis/montecarlo/montecarlo_numba/formal_integral.py
index b4b791b1b37..0c7d3c6627c 100644
--- a/tardis/montecarlo/montecarlo_numba/formal_integral.py
+++ b/tardis/montecarlo/montecarlo_numba/formal_integral.py
@@ -6,7 +6,8 @@
 from scipy.interpolate import interp1d
 from astropy import units as u
 from tardis import constants as const
-from numba import njit, char, float64, int64, jitclass, typeof, byte, prange
+from numba import njit, char, float64, int64, typeof, byte, prange
+from numba.experimental import jitclass
 import pdb
 
 from tardis.montecarlo.montecarlo_numba.numba_config import SIGMA_THOMSON
diff --git a/tardis_env3.yml b/tardis_env3.yml
index a10de0ac238..6ffd66c46da 100644
--- a/tardis_env3.yml
+++ b/tardis_env3.yml
@@ -10,7 +10,7 @@ dependencies:
   - scipy=1.5
   - pandas=1.0
   - astropy=3
-  - numba=0.50
+  - numba=0.53.1
   - numexpr
 
   # Plasma