diff --git a/libs/langchain/langchain/llms/bedrock.py b/libs/langchain/langchain/llms/bedrock.py
index 7d07f92662..8fd22351a7 100644
--- a/libs/langchain/langchain/llms/bedrock.py
+++ b/libs/langchain/langchain/llms/bedrock.py
@@ -8,6 +8,52 @@ from langchain.llms.utils import enforce_stop_tokens
 from langchain.pydantic_v1 import BaseModel, Extra, root_validator
 from langchain.schema.output import GenerationChunk
 
+HUMAN_PROMPT = "\n\nHuman:"
+ASSISTANT_PROMPT = "\n\nAssistant:"
+ALTERNATION_ERROR = (
+    "Error: Prompt must alternate between '\n\nHuman:' and '\n\nAssistant:'."
+)
+
+
+def _add_newlines_before_ha(input_text: str) -> str:
+    new_text = input_text
+    for word in ["Human:", "Assistant:"]:
+        new_text = new_text.replace(word, "\n\n" + word)
+        for i in range(2):
+            new_text = new_text.replace("\n\n\n" + word, "\n\n" + word)
+    return new_text
+
+
+def _human_assistant_format(input_text: str) -> str:
+    if input_text.count("Human:") == 0 or (
+        input_text.find("Human:") > input_text.find("Assistant:")
+        and "Assistant:" in input_text
+    ):
+        input_text = HUMAN_PROMPT + " " + input_text  # SILENT CORRECTION
+    if input_text.count("Assistant:") == 0:
+        input_text = input_text + ASSISTANT_PROMPT  # SILENT CORRECTION
+    if input_text[: len("Human:")] == "Human:":
+        input_text = "\n\n" + input_text
+    input_text = _add_newlines_before_ha(input_text)
+    count = 0
+    # track alternation
+    for i in range(len(input_text)):
+        if input_text[i : i + len(HUMAN_PROMPT)] == HUMAN_PROMPT:
+            if count % 2 == 0:
+                count += 1
+            else:
+                raise ValueError(ALTERNATION_ERROR)
+        if input_text[i : i + len(ASSISTANT_PROMPT)] == ASSISTANT_PROMPT:
+            if count % 2 == 1:
+                count += 1
+            else:
+                raise ValueError(ALTERNATION_ERROR)
+
+    if count % 2 == 1:  # Only saw Human, no Assistant
+        input_text = input_text + ASSISTANT_PROMPT  # SILENT CORRECTION
+
+    return input_text
+
 
 class LLMInputOutputAdapter:
     """Adapter class to prepare the inputs from Langchain to a format
@@ -26,7 +72,9 @@ class LLMInputOutputAdapter:
         cls, provider: str, prompt: str, model_kwargs: Dict[str, Any]
     ) -> Dict[str, Any]:
         input_body = {**model_kwargs}
-        if provider == "anthropic" or provider == "ai21":
+        if provider == "anthropic":
+            input_body["prompt"] = _human_assistant_format(prompt)
+        elif provider == "ai21":
             input_body["prompt"] = prompt
         elif provider == "amazon":
             input_body = dict()
diff --git a/libs/langchain/tests/unit_tests/llms/test_bedrock.py b/libs/langchain/tests/unit_tests/llms/test_bedrock.py
new file mode 100644
index 0000000000..985011c277
--- /dev/null
+++ b/libs/langchain/tests/unit_tests/llms/test_bedrock.py
@@ -0,0 +1,252 @@
+import pytest
+
+from langchain.llms.bedrock import ALTERNATION_ERROR, _human_assistant_format
+
+TEST_CASES = {
+    """Hey""": """
+
+Human: Hey
+
+Assistant:""",
+    """
+
+Human: Hello
+
+Assistant:""": """
+
+Human: Hello
+
+Assistant:""",
+    """Human: Hello
+
+Assistant:""": """
+
+Human: Hello
+
+Assistant:""",
+    """
+Human: Hello
+
+Assistant:""": """
+
+Human: Hello
+
+Assistant:""",
+    """
+
+Human: Human: Hello
+
+Assistant:""": (
+        "Error: Prompt must alternate between '\n\nHuman:' and '\n\nAssistant:'."
+    ),
+    """Human: Hello
+
+Assistant: Hello
+
+Human: Hello
+
+Assistant:""": """
+
+Human: Hello
+
+Assistant: Hello
+
+Human: Hello
+
+Assistant:""",
+    """
+
+Human: Hello
+
+Assistant: Hello
+
+Human: Hello
+
+Assistant:""": """
+
+Human: Hello
+
+Assistant: Hello
+
+Human: Hello
+
+Assistant:""",
+    """
+
+Human: Hello
+
+Assistant: Hello
+
+Human: Hello
+
+Assistant: Hello
+
+Assistant: Hello""": ALTERNATION_ERROR,
+    """
+
+Human: Hi.
+
+Assistant: Hi.
+
+Human: Hi.
+
+Human: Hi.
+
+Assistant:""": ALTERNATION_ERROR,
+    """
+Human: Hello""": """
+
+Human: Hello
+
+Assistant:""",
+    """
+
+Human: Hello
+Hello
+
+Assistant""": """
+
+Human: Hello
+Hello
+
+Assistant
+
+Assistant:""",
+    """Hello
+
+Assistant:""": """
+
+Human: Hello
+
+Assistant:""",
+    """Hello
+
+Human: Hello
+
+""": """Hello
+
+Human: Hello
+
+
+
+Assistant:""",
+    """
+
+Human: Assistant: Hello""": """
+
+Human: 
+
+Assistant: Hello""",
+    """
+
+Human: Human
+
+Assistant: Assistant
+
+Human: Assistant
+
+Assistant: Human""": """
+
+Human: Human
+
+Assistant: Assistant
+
+Human: Assistant
+
+Assistant: Human""",
+    """
+Assistant: Hello there, your name is:
+
+Human.
+
+Human: Hello there, your name is: 
+
+Assistant.""": """
+
+Human: 
+
+Assistant: Hello there, your name is:
+
+Human.
+
+Human: Hello there, your name is: 
+
+Assistant.
+
+Assistant:""",
+    """
+
+Human: Human: Hi
+
+Assistant: Hi""": ALTERNATION_ERROR,
+    """Human: Hi
+
+Human: Hi""": ALTERNATION_ERROR,
+    """
+
+Assistant: Hi
+
+Human: Hi""": """
+
+Human: 
+
+Assistant: Hi
+
+Human: Hi
+
+Assistant:""",
+    """
+
+Human: Hi
+
+Assistant: Yo
+
+Human: Hey
+
+Assistant: Sup
+
+Human: Hi
+
+Assistant: Hi
+Human: Hi
+Assistant:""": """
+
+Human: Hi
+
+Assistant: Yo
+
+Human: Hey
+
+Assistant: Sup
+
+Human: Hi
+
+Assistant: Hi
+
+Human: Hi
+
+Assistant:""",
+    """
+
+Hello.
+
+Human: Hello.
+
+Assistant:""": """
+
+Hello.
+
+Human: Hello.
+
+Assistant:""",
+}
+
+
+def test__human_assistant_format() -> None:
+    for input_text, expected_output in TEST_CASES.items():
+        if expected_output == ALTERNATION_ERROR:
+            with pytest.raises(ValueError):
+                _human_assistant_format(input_text)
+        else:
+            output = _human_assistant_format(input_text)
+            assert output == expected_output