diff --git a/src/molecules/dropdown-button/dropdown-button.test.tsx b/src/molecules/dropdown-button/dropdown-button.test.tsx
index 10965b7..839dbb6 100644
--- a/src/molecules/dropdown-button/dropdown-button.test.tsx
+++ b/src/molecules/dropdown-button/dropdown-button.test.tsx
@@ -56,7 +56,7 @@ describe("DropdownButton", () => {
                 size={testButtonSize}
             />
         );
-        const result = container.getElementsByClassName(testButtonSize);
+        const result = container.getElementsByClassName(`-${testButtonSize}`);
 
         // Assert
         expect(result).toHaveLength(1);
@@ -75,7 +75,7 @@ describe("DropdownButton", () => {
                 style={testButtonStyle}
             />
         );
-        const result = container.getElementsByClassName(testButtonStyle);
+        const result = container.getElementsByClassName(`-${testButtonStyle}`);
 
         // Assert
         expect(result).toHaveLength(1);
diff --git a/src/molecules/dropdown-button/dropdown-button.tsx b/src/molecules/dropdown-button/dropdown-button.tsx
index 18a83d1..16e2cb3 100644
--- a/src/molecules/dropdown-button/dropdown-button.tsx
+++ b/src/molecules/dropdown-button/dropdown-button.tsx
@@ -50,11 +50,11 @@ const DropdownButton: React.FC<DropdownButtonProps> = (
     }
 
     if (size != null) {
-        classNames.push(size);
+        classNames.push(`-${size}`);
     }
 
     if (style != null) {
-        classNames.push(style);
+        classNames.push(`-${style}`);
     }
 
     return (