diff --git a/ppanggolin/genome.py b/ppanggolin/genome.py
index 743a4eb4..f1ebb682 100644
--- a/ppanggolin/genome.py
+++ b/ppanggolin/genome.py
@@ -362,7 +362,7 @@ def length(self, contig_len: int):
 
         if self.length is None:
             self._length = contig_len
-        elif self.length != contig_length:
+        elif self.length != contig_len:
             raise ValueError('Attempting to define a contig length different from the previously defined value.')
         
 
diff --git a/ppanggolin/region.py b/ppanggolin/region.py
index da434858..a2abcc3c 100644
--- a/ppanggolin/region.py
+++ b/ppanggolin/region.py
@@ -746,7 +746,7 @@ def organisms(self) -> Generator[Organism, None, None]:
         organisms = set()
         for fam in self.families:
             organisms |= set(fam.organisms)
-        return organisms
+        yield from organisms
 
 
     def mk_bitarray(self, index: Dict[Organism, int], partition: str = 'all'):