diff --git a/src/helm/benchmark/metrics/vision_language/image_metrics.py b/src/helm/benchmark/metrics/vision_language/image_metrics.py
index bd8803d4d2..f7d0b24334 100644
--- a/src/helm/benchmark/metrics/vision_language/image_metrics.py
+++ b/src/helm/benchmark/metrics/vision_language/image_metrics.py
@@ -304,7 +304,7 @@ def lpips_similarity(self, generated_image: Image.Image, reference_image: Image.
             with warnings.catch_warnings():
                 warnings.filterwarnings("ignore", category=UserWarning)
                 # https://lightning.ai/docs/torchmetrics/stable/image/learned_perceptual_image_patch_similarity.html
-                self._lpips_metric = 1 - LearnedPerceptualImagePatchSimilarity(net_type="vgg", normalize=True).to(
+                self._lpips_metric = 1.0 - LearnedPerceptualImagePatchSimilarity(net_type="vgg", normalize=True).to(
                     self._device
                 )