diff --git a/gprMax/model_build_run.py b/gprMax/model_build_run.py
index d5694b90..179848a7 100644
--- a/gprMax/model_build_run.py
+++ b/gprMax/model_build_run.py
@@ -252,12 +252,12 @@ def run_model(args, currentmodelrun, numbermodelruns, inputfile, usernamespace):
             print('Memory (RAM) used: ~{}'.format(human_size(p.memory_info().rss)))
             print('Solving time [HH:MM:SS]: {}'.format(datetime.timedelta(seconds=tsolve)))
 
-        # If geometry information to be reused between model runs then FDTDGrid class instance must be global so that it persists
-        if not args.geometry_fixed:
-            del G
-
         return tsolve
 
+    # If geometry information to be reused between model runs then FDTDGrid class instance must be global so that it persists
+    if not args.geometry_fixed:
+        del G
+
 
 def solve_cpu(currentmodelrun, numbermodelruns, G):
     """Solving using FDTD method on CPU. Parallelised using Cython (OpenMP) for electric and magnetic field updates, and PML updates.