diff --git a/libs/langchain_v1/langchain/chat_models/base.py b/libs/langchain_v1/langchain/chat_models/base.py
index 7f47772321e..89a8b00e53a 100644
--- a/libs/langchain_v1/langchain/chat_models/base.py
+++ b/libs/langchain_v1/langchain/chat_models/base.py
@@ -501,7 +501,7 @@ def _attempt_infer_model_provider(model_name: str) -> str | None:
         return "cohere"
 
     # Fireworks models
-    if model_name.startswith("accounts/fireworks"):
+    if model_lower.startswith("accounts/fireworks"):
         return "fireworks"
 
     # Google models
@@ -509,7 +509,7 @@ def _attempt_infer_model_provider(model_name: str) -> str | None:
         return "google_vertexai"
 
     # AWS Bedrock models
-    if model_name.startswith("amazon.") or model_lower.startswith(("anthropic.", "meta.")):
+    if model_lower.startswith(("amazon.", "anthropic.", "meta.")):
         return "bedrock"
 
     # Mistral models
diff --git a/libs/langchain_v1/tests/unit_tests/chat_models/test_chat_models.py b/libs/langchain_v1/tests/unit_tests/chat_models/test_chat_models.py
index bdbb39d4006..9f9f341fd63 100644
--- a/libs/langchain_v1/tests/unit_tests/chat_models/test_chat_models.py
+++ b/libs/langchain_v1/tests/unit_tests/chat_models/test_chat_models.py
@@ -78,11 +78,14 @@ def test_supported_providers_is_sorted() -> None:
         ("claude-3-haiku-20240307", "anthropic"),
         ("command-r-plus", "cohere"),
         ("accounts/fireworks/models/mixtral-8x7b-instruct", "fireworks"),
+        ("Accounts/Fireworks/models/mixtral-8x7b-instruct", "fireworks"),
         ("gemini-1.5-pro", "google_vertexai"),
         ("gemini-2.5-pro", "google_vertexai"),
         ("gemini-3-pro-preview", "google_vertexai"),
         ("amazon.titan-text-express-v1", "bedrock"),
+        ("Amazon.Titan-Text-Express-v1", "bedrock"),
         ("anthropic.claude-v2", "bedrock"),
+        ("Anthropic.Claude-V2", "bedrock"),
         ("mistral-small", "mistralai"),
         ("mixtral-8x7b", "mistralai"),
         ("deepseek-v3", "deepseek"),