diff --git a/litellm/litellm_core_utils/llm_response_utils/get_formatted_prompt.py b/litellm/litellm_core_utils/llm_response_utils/get_formatted_prompt.py
index 0e87050d74c..0d60a791e57 100644
--- a/litellm/litellm_core_utils/llm_response_utils/get_formatted_prompt.py
+++ b/litellm/litellm_core_utils/llm_response_utils/get_formatted_prompt.py
@@ -40,7 +40,9 @@ def get_formatted_prompt(
         if isinstance(data["input"], str):
             prompt = data["input"]
         elif isinstance(data["input"], list):
-            prompt = "".join(item for item in data["input"] if isinstance(item, str))
+            for item in data["input"]:
+                if isinstance(item, str):
+                    prompt += item
     elif call_type == "image_generation":
         prompt = data["prompt"]
     elif call_type == "audio_transcription":
diff --git a/litellm/proxy/hooks/prompt_injection_detection.py b/litellm/proxy/hooks/prompt_injection_detection.py
index d8615d53dc0..a26c61ab3aa 100644
--- a/litellm/proxy/hooks/prompt_injection_detection.py
+++ b/litellm/proxy/hooks/prompt_injection_detection.py
@@ -147,7 +147,11 @@ class _OPTIONAL_PromptInjectionDetection(CustomLogger):
                     return True  # Found a highly similar substring
         return False  # No substring crossed the threshold
 
-    def _formatted_prompt(self, data: dict[str, object], call_type: CallTypesLiteral) -> str | None:
+    def _formatted_prompt(
+        self,
+        data: dict[str, object],  # mutable-ok: forwarded as-is to get_formatted_prompt, which takes the request dict
+        call_type: CallTypesLiteral,
+    ) -> str | None:
         if call_type in ("completion", "acompletion"):
             return get_formatted_prompt(data=data, call_type="completion")
         if call_type in ("text_completion", "atext_completion"):
diff --git a/tests/unit/litellm_core_utils/llm_response_utils/test_get_formatted_prompt.py b/tests/unit/litellm_core_utils/llm_response_utils/test_get_formatted_prompt.py
index 64dd79bb918..05c2890169d 100644
--- a/tests/unit/litellm_core_utils/llm_response_utils/test_get_formatted_prompt.py
+++ b/tests/unit/litellm_core_utils/llm_response_utils/test_get_formatted_prompt.py
@@ -22,3 +22,11 @@ def test_null_tool_calls_are_skipped(call_type: Literal["acompletion", "completi
     }
 
     assert get_formatted_prompt(data=data, call_type=call_type) == 'pingpong{"x":1}'
+
+
+@pytest.mark.parametrize("call_type", ["embedding", "moderation"])
+def test_non_string_list_input_is_skipped(call_type: Literal["embedding", "moderation"]) -> None:
+    """/v1/embeddings accepts token id arrays, so the input list is not always text."""
+    data: Final = {"input": ["scan me", 1234, ["nested"], "and me"]}
+
+    assert get_formatted_prompt(data=data, call_type=call_type) == "scan meand me"