diff --git a/src/GEOReverse/Modules/MCNPinput.py b/src/GEOReverse/Modules/MCNPinput.py
index f3f6a799..ddf8173f 100644
--- a/src/GEOReverse/Modules/MCNPinput.py
+++ b/src/GEOReverse/Modules/MCNPinput.py
@@ -289,6 +289,9 @@ def selectCells(cellList,config):
     for cname,c in selected.items() :
        c.geom = remove_hash(cellList,cname)
 
+    if not selected:
+        raise ValueError("No cells selected. Check input or selection criteria in config file.")
+
     return selected    
         
 #Change implicit cell definition (like-but type or cell with #)
diff --git a/src/GEOReverse/Modules/XMLinput.py b/src/GEOReverse/Modules/XMLinput.py
index fcd9eacc..5def4f8a 100644
--- a/src/GEOReverse/Modules/XMLinput.py
+++ b/src/GEOReverse/Modules/XMLinput.py
@@ -211,6 +211,9 @@ def selectCells(cellList,config):
     # remove complementary in cell of the universe
     # for cname,c in selected.items() :
     #   c.geom = remove_hash(cellList,cname)
+    
+    if not selected:
+        raise ValueError("No cells selected. Check input or selection criteria in config file.")
 
     return selected