diff --git a/arrow/arrow.py b/arrow/arrow.py
index eecf23266..6db40b3b4 100644
--- a/arrow/arrow.py
+++ b/arrow/arrow.py
@@ -1394,6 +1394,11 @@ def dehumanize(self, input_string: str, locale: str = "en_us") -> "Arrow":
         # Create a regex pattern object for numbers
         num_pattern = re.compile(r"\d+")
 
+        if not isinstance(input_string, str):
+            raise TypeError(
+                f"input_string must be str, not {type(input_string).__name__}."
+            )
+
         # Search input string for each time unit within locale
         for unit, unit_object in locale_obj.timeframes.items():
             # Need to check the type of unit_object to create the correct dictionary
diff --git a/tests/test_arrow.py b/tests/test_arrow.py
index b595e4e21..edd197c19 100644
--- a/tests/test_arrow.py
+++ b/tests/test_arrow.py
@@ -2868,6 +2868,14 @@ def test_normalized_locale(self):
         assert arw.dehumanize(second_ago_string, locale="zh_hk") == second_ago
         assert arw.dehumanize(second_future_string, locale="zh_hk") == second_future
 
+    # Non-str input should raise a clear TypeError rather than crashing
+    # deep in the regex / timeframes iteration with AttributeError.
+    def test_non_str_input_raises_typeerror(self):
+        arw = arrow.Arrow(2024, 1, 1)
+        for bad in (123, None, [1, 2], b"bytes"):
+            with pytest.raises(TypeError, match="input_string must be str"):
+                arw.dehumanize(bad)
+
     # Ensures relative units are required in string
     def test_require_relative_unit(self, locale_list_no_weeks: List[str]):
         for lang in locale_list_no_weeks: