diff --git a/src/spirit/include/adjust_duty_cycle.h b/src/spirit/include/adjust_duty_cycle.h
index e4568c6..0055576 100644
--- a/src/spirit/include/adjust_duty_cycle.h
+++ b/src/spirit/include/adjust_duty_cycle.h
@@ -21,10 +21,31 @@ namespace spirit {
  * @note
  * Motor::State::Coast, Motor::State::Brake は必ずデューティー比を0として扱う
  */
-void adjust_duty_cycle(spirit::Motor::State target_state, float target_duty_cycle, float max_rise_delta,
-                       float max_fall_delta, spirit::Motor::State current_state, float current_duty_cycle,
-                       spirit::Motor::State& next_state, float& next_duty_cycle)
+void adjust_duty_cycle(Motor::State target_state, float target_duty_cycle, float max_rise_delta, float max_fall_delta,
+                       Motor::State current_state, float current_duty_cycle, Motor::State& next_state,
+                       float& next_duty_cycle)
 {
+    /**
+     * @brief stateの範囲チェック
+     * @param type チェックしたい回転方向
+     */
+    auto within_state = [](Motor::State type) {
+        switch (type) {
+            case Motor::State::Coast:
+            case Motor::State::CW:
+            case Motor::State::CCW:
+            case Motor::State::Brake:
+                break;
+            default:
+                Error::get_instance().error(Error::Type::UnknownValue, 0, __FILE__, __func__, __LINE__,
+                                            "Unknown motor state (%d)", static_cast<uint32_t>(type));
+                return;
+        }
+    };
+
+    within_state(target_state);
+    within_state(current_state);
+
     // 回転方向がCoast or Brakeの場合は現在のデューティー比を0として扱う
     if ((target_state == Motor::State::Coast) || (target_state == Motor::State::Brake)) {
         target_duty_cycle = 0.00F;
diff --git a/tests/test_adjust_duty_cycle.cpp b/tests/test_adjust_duty_cycle.cpp
index b61eaec..70487c9 100644
--- a/tests/test_adjust_duty_cycle.cpp
+++ b/tests/test_adjust_duty_cycle.cpp
@@ -1,5 +1,6 @@
 #include <gtest/gtest.h>
 
+#include "Error.h"
 #include "Motor.h"
 #include "adjust_duty_cycle.h"
 
@@ -374,5 +375,38 @@ TEST(AdjustDutyCycle, Normal)
         }
     }
 }
+TEST(adjust_duty_cycle, AnomalyTest)
+{
+    Motor::State next_state;
+    float        next_duty_cycle;
+
+    // Error時に標準エラー出力に文字列が出力される
+    // 本当のエラー時にエラー出力させたいので、異常系のテスト中は標準エラー出力をキャプチャする
+    testing::internal::CaptureStderr();
+
+    Error& error = Error::get_instance();
+    EXPECT_EQ(error.get_status(), Error::Status::Normal);
+
+    /// @test target_stateが範囲外の時にエラーになることのテスト
+    error.reset();
+    EXPECT_EQ(error.get_status(), Error::Status::Normal);
+    adjust_duty_cycle(static_cast<Motor::State>(4), 0.00F, 0.50F, 0.50F, Motor::State::Coast, 0.00F, next_state,
+                      next_duty_cycle);
+    EXPECT_EQ(error.get_status(), Error::Status::Error);
+
+    /// @test current_stateが範囲外の時にエラーになることのテスト
+    error.reset();
+    EXPECT_EQ(error.get_status(), Error::Status::Normal);
+    adjust_duty_cycle(Motor::State::Coast, 0.00F, 0.50F, 0.50F, static_cast<Motor::State>(4), 0.00F, next_state,
+                      next_duty_cycle);
+    EXPECT_EQ(error.get_status(), Error::Status::Error);
+
+    /// @test target_stateとcurrent_stateが範囲外の時にエラーになることのテスト
+    error.reset();
+    EXPECT_EQ(error.get_status(), Error::Status::Normal);
+    adjust_duty_cycle(static_cast<Motor::State>(4), 0.00F, 0.50F, 0.50F, static_cast<Motor::State>(4), 0.00F,
+                      next_state, next_duty_cycle);
+    EXPECT_EQ(error.get_status(), Error::Status::Error);
+}
 
 }  // namespace