--- a/taskcluster/taskgraph/transforms/l10n.py
+++ b/taskcluster/taskgraph/transforms/l10n.py
@@ -243,16 +243,19 @@ def all_locales_attribute(config, jobs):
 
 @transforms.add
 def chunk_locales(config, jobs):
     """ Utilizes chunking for l10n stuff """
     for job in jobs:
         chunks = job.get('chunks')
         all_locales = job['attributes']['all_locales']
         if chunks:
+            if chunks > len(all_locales):
+                # Reduce chunks down to the number of locales
+                chunks = len(all_locales)
             for this_chunk in range(1, chunks + 1):
                 chunked = copy.deepcopy(job)
                 chunked['name'] = chunked['name'].replace(
                     '/', '-{}/'.format(this_chunk), 1
                 )
                 chunked['mozharness']['options'] = chunked['mozharness'].get('options', [])
                 my_locales = []
                 my_locales = chunkify(all_locales, this_chunk, chunks)