diff --git a/CHANGELOG.md b/CHANGELOG.md
index 295c88cb6..ebb578ae2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,12 @@ Note that Sockeye has checks in place to not translate with an old model that wa
 
 Each version section may have subsections for: _Added_, _Changed_, _Removed_, _Deprecated_, and _Fixed_.
 
+## [3.1.9]
+
+### Changed
+
+- Clarified usage of `batch_size` in Translator code.
+
 ## [3.1.8]
 
 ### Fixed
diff --git a/sockeye/__init__.py b/sockeye/__init__.py
index 192ff98d4..e0ef9df6c 100644
--- a/sockeye/__init__.py
+++ b/sockeye/__init__.py
@@ -11,4 +11,4 @@
 # express or implied. See the License for the specific language governing
 # permissions and limitations under the License.
 
-__version__ = '3.1.8'
+__version__ = '3.1.9'
diff --git a/sockeye/inference.py b/sockeye/inference.py
index 757096f02..ff6b2bf63 100644
--- a/sockeye/inference.py
+++ b/sockeye/inference.py
@@ -1200,7 +1200,7 @@ def _get_best_translations(self, result: SearchResult) -> List[Translation]:
         batch_size = best_hyp_indices.shape[0] // self.beam_size
         nbest_translations = []  # type: List[List[Translation]]
         reference_lengths = estimated_reference_lengths \
-            if estimated_reference_lengths is not None else np.zeros((self.batch_size * self.beam_size, 1))
+            if estimated_reference_lengths is not None else np.zeros((batch_size * self.beam_size, 1))
         for n in range(0, self.nbest_size):
 
             # Initialize the best_ids to the first item in each batch, plus current nbest index
diff --git a/sockeye/translate.py b/sockeye/translate.py
index 511b5e4a0..839b33aa7 100644
--- a/sockeye/translate.py
+++ b/sockeye/translate.py
@@ -211,7 +211,6 @@ def read_and_translate(translator: inference.Translator,
     :param input_factors: Optional list of paths to files that contain source factors.
     :param input_is_json: Whether the input is in json format.
     """
-    batch_size = translator.max_batch_size
     if chunk_size is None:
         if translator.max_batch_size == 1:
             # No batching, therefore there is not need to read segments in chunks.
@@ -222,8 +221,8 @@ def read_and_translate(translator: inference.Translator,
     else:
         if chunk_size < translator.max_batch_size:
             logger.warning("You specified a chunk size (%d) smaller than the max batch size (%d). This will lead to "
-                           "a reduction in translation speed. Consider choosing a larger chunk size." % (chunk_size,
-                                                                                                         batch_size))
+                           "a reduction in translation speed. Consider choosing a larger chunk size.",
+                           chunk_size, translator.max_batch_size)
 
     logger.info("Translating...")