diff --git a/server/text_generation_server/models/custom_modeling/opt_modeling.py b/server/text_generation_server/models/custom_modeling/opt_modeling.py
index b0d05f43..bd440321 100644
--- a/server/text_generation_server/models/custom_modeling/opt_modeling.py
+++ b/server/text_generation_server/models/custom_modeling/opt_modeling.py
@@ -99,7 +99,7 @@ class OPTLearnedPositionalEmbedding(nn.Module):
         self.offset = 2
         self.weight = nn.Parameter(
             weights.get_tensor(
-                f"{prefix and prefix + '.'}decoder.embed_positions.weight"
+                f"{prefix + '.' if prefix else ''}decoder.embed_positions.weight"
             )
         )
 
@@ -317,7 +317,7 @@ class OPTDecoderLayer(nn.Module):
         super().__init__()
         self.process_group = weights.process_group
         self.hidden_size = config.hidden_size
-        prefix = f"{prefix and prefix + '.'}decoder.layers.{layer_id}"
+        prefix = f"{prefix + '.' if prefix else ''}decoder.layers.{layer_id}"
         self.self_attn = OPTAttention(
             config,
             prefix=f"{prefix}.self_attn",
@@ -439,7 +439,7 @@ class OPTDecoder(OPTPreTrainedModel):
         self.max_target_positions = config.max_position_embeddings
         self.vocab_size = config.vocab_size
 
-        prefix = prefix and prefix + "."
+        prefix = prefix + "." if prefix else ""
 
         self.embed_tokens = TensorParallelEmbedding(
             prefix=f"{prefix}decoder.embed_tokens", weights=weights
@@ -760,7 +760,7 @@ class OPTForCausalLM(OPTPreTrainedModel):
 
         self.lm_head = SpeculativeHead.load(
             config,
-            prefix=f"{prefix and prefix + '.'}decoder.embed_tokens",
+            prefix=f"{prefix + '.' if prefix else ''}decoder.embed_tokens",
             weights=weights,
         )