diff --git a/lib/crewai/src/crewai/llms/providers/gemini/completion.py b/lib/crewai/src/crewai/llms/providers/gemini/completion.py
index 0bdf8ec0ea..85799873d7 100644
--- a/lib/crewai/src/crewai/llms/providers/gemini/completion.py
+++ b/lib/crewai/src/crewai/llms/providers/gemini/completion.py
@@ -1361,24 +1361,28 @@ def get_context_window_size(self) -> int:
                     f"Context window for {key} must be between {min_context} and {max_context}"
                 )
 
+        # Longest prefix first. Always insert new keys in that order so
+        # startswith prefers gemini-2.0-flash-thinking over gemini-2.0-flash, etc.
         context_windows = {
             "gemini-3-pro-preview": 1048576,  # 1M tokens
-            "gemini-2.0-flash": 1048576,  # 1M tokens
             "gemini-2.0-flash-thinking": 32768,
             "gemini-2.0-flash-lite": 1048576,
+            "gemini-2.0-flash": 1048576,  # 1M tokens
             "gemini-2.5-flash": 1048576,
             "gemini-2.5-pro": 1048576,
             "gemini-1.5-pro": 2097152,  # 2M tokens
-            "gemini-1.5-flash": 1048576,
             "gemini-1.5-flash-8b": 1048576,
+            "gemini-1.5-flash": 1048576,
             "gemini-1.0-pro": 32768,
-            "gemma-3-1b": 32000,
-            "gemma-3-4b": 128000,
-            "gemma-3-12b": 128000,
             "gemma-3-27b": 128000,
+            "gemma-3-12b": 128000,
+            "gemma-3-4b": 128000,
+            "gemma-3-1b": 32000,
         }
 
-        for model_prefix, size in context_windows.items():
+        for model_prefix, size in sorted(
+            context_windows.items(), key=lambda item: len(item[0]), reverse=True
+        ):
             if self.model.startswith(model_prefix):
                 return int(size * CONTEXT_WINDOW_USAGE_RATIO)
 
diff --git a/lib/crewai/tests/test_llm.py b/lib/crewai/tests/test_llm.py
index 51c87cd0ea..bef7d44b92 100644
--- a/lib/crewai/tests/test_llm.py
+++ b/lib/crewai/tests/test_llm.py
@@ -386,6 +386,18 @@ def test_unrecognized_provider_prefix_is_not_stripped() -> None:
     )
 
 
+def test_gemini_thinking_context_window() -> None:
+    """Gemini thinking models must not be shadowed by gemini-2.0-flash prefix."""
+    from crewai.llms.providers.gemini.completion import GeminiCompletion
+
+    gemini_thinking = GeminiCompletion(model="gemini-2.0-flash-thinking-exp-01-21")
+    assert gemini_thinking.get_context_window_size() == int(32768 * CONTEXT_WINDOW_USAGE_RATIO)
+
+    gemini_flash = GeminiCompletion(model="gemini-2.0-flash-001")
+    assert gemini_flash.get_context_window_size() == int(1048576 * CONTEXT_WINDOW_USAGE_RATIO)
+
+
+
 @pytest.fixture
 def get_weather_tool_schema():
     return {