diff --git a/recipes/deepseek-v32-fp4/trtllm/agg-round-robin/perf.yaml b/recipes/deepseek-v32-fp4/trtllm/agg-round-robin/perf.yaml
index 4aa14675003a..eef7c962efc6 100644
--- a/recipes/deepseek-v32-fp4/trtllm/agg-round-robin/perf.yaml
+++ b/recipes/deepseek-v32-fp4/trtllm/agg-round-robin/perf.yaml
@@ -49,7 +49,13 @@ spec:
           echo 1024 > /proc/sys/fs/inotify/max_user_instances 2>/dev/null || true
           apt-get update && apt-get install -y curl jq procps git && apt-get clean
           # pip install git+https://github.com/ai-dynamo/aiperf.git
-          pip install aiperf==0.6.0
+          # Pin transformers==4.57.6 (verified to load the deepseek_v32 tokenizer).
+          # The trtllm-runtime base ships transformers 4.55.0; aiperf 0.6.0's
+          # `transformers>=4.56.0` floor would otherwise upgrade to 5.x, which lacks
+          # native support for model_type=deepseek_v32 (huggingface/transformers#41251)
+          # and fails AutoTokenizer.from_pretrained() before reading tokenizer.json.
+          # aiperf surfaces this as "Failed to load tokenizer". DYN-2878.
+          pip install "aiperf==0.6.0" "transformers==4.57.6"
           echo "aiperf installation completed"
           sysctl -w net.ipv4.ip_local_port_range="1024 65000" 2>/dev/null || true
           export COLUMNS=200
diff --git a/recipes/deepseek-v32-fp4/trtllm/disagg-kv-router/perf.yaml b/recipes/deepseek-v32-fp4/trtllm/disagg-kv-router/perf.yaml
index dcfd7959fc6f..7515449545fa 100644
--- a/recipes/deepseek-v32-fp4/trtllm/disagg-kv-router/perf.yaml
+++ b/recipes/deepseek-v32-fp4/trtllm/disagg-kv-router/perf.yaml
@@ -49,7 +49,13 @@ spec:
           echo 1024 > /proc/sys/fs/inotify/max_user_instances 2>/dev/null || true
           apt-get update && apt-get install -y curl jq procps git && apt-get clean
           # pip install git+https://github.com/ai-dynamo/aiperf.git
-          pip install aiperf==0.6.0
+          # Pin transformers==4.57.6 (verified to load the deepseek_v32 tokenizer).
+          # The trtllm-runtime base ships transformers 4.55.0; aiperf 0.6.0's
+          # `transformers>=4.56.0` floor would otherwise upgrade to 5.x, which lacks
+          # native support for model_type=deepseek_v32 (huggingface/transformers#41251)
+          # and fails AutoTokenizer.from_pretrained() before reading tokenizer.json.
+          # aiperf surfaces this as "Failed to load tokenizer". DYN-2878.
+          pip install "aiperf==0.6.0" "transformers==4.57.6"
           echo "aiperf installation completed"
           sysctl -w net.ipv4.ip_local_port_range="1024 65000" 2>/dev/null || true
           export COLUMNS=200