diff --git a/include/vcl/BitmapAlphaClampFilter.hxx b/include/vcl/BitmapAlphaClampFilter.hxx
index 8ff8a8d91867..21163862af4c 100644
--- a/include/vcl/BitmapAlphaClampFilter.hxx
+++ b/include/vcl/BitmapAlphaClampFilter.hxx
@@ -10,12 +10,11 @@
 
 #pragma once
 
-#include <config_options.h>
 #include <vcl/BitmapFilter.hxx>
 
 /** If the alpha is beyond a certain threshold, make it fully transparent
  */
-class UNLESS_MERGELIBS(VCL_DLLPUBLIC) BitmapAlphaClampFilter final : public BitmapFilter
+class VCL_DLLPUBLIC BitmapAlphaClampFilter final : public BitmapFilter
 {
 public:
     BitmapAlphaClampFilter(sal_uInt8 cThreshold)
diff --git a/vcl/qa/cppunit/BitmapFilterTest.cxx b/vcl/qa/cppunit/BitmapFilterTest.cxx
index e492b963f48d..099720a1569d 100644
--- a/vcl/qa/cppunit/BitmapFilterTest.cxx
+++ b/vcl/qa/cppunit/BitmapFilterTest.cxx
@@ -15,6 +15,7 @@
 #include <tools/stream.hxx>
 #include <vcl/graphicfilter.hxx>
 
+#include <vcl/BitmapAlphaClampFilter.hxx>
 #include <vcl/BitmapArithmeticBlendFilter.hxx>
 #include <vcl/BitmapDarkenBlendFilter.hxx>
 #include <vcl/BitmapLightenBlendFilter.hxx>
@@ -41,6 +42,7 @@ public:
     {
     }
 
+    void testClampAlpha();
     void testBlurCorrectness();
     void testBasicMorphology();
     void testPerformance();
@@ -53,6 +55,7 @@ public:
     void testArithmeticBlendFilter();
 
     CPPUNIT_TEST_SUITE(BitmapFilterTest);
+    CPPUNIT_TEST(testClampAlpha);
     CPPUNIT_TEST(testBlurCorrectness);
     CPPUNIT_TEST(testBasicMorphology);
     CPPUNIT_TEST(testPerformance);
@@ -91,6 +94,22 @@ private:
     }
 };
 
+void BitmapFilterTest::testClampAlpha()
+{
+    // Setup test bitmap
+    Size aSize(1, 1);
+    Bitmap aBitmap24Bit(aSize, vcl::PixelFormat::N24_BPP);
+
+    {
+        BitmapScopedWriteAccess aWriteAccess(aBitmap24Bit);
+        aWriteAccess->Erase(COL_RED);
+    }
+
+    BitmapEx aBitmapEx24Bit(aBitmap24Bit);
+    BitmapFilter::Filter(aBitmapEx24Bit, BitmapAlphaClampFilter(0x7F));
+    CPPUNIT_ASSERT_EQUAL(static_cast<sal_uInt8>(0xFF), aBitmapEx24Bit.GetAlpha(0, 0));
+}
+
 void BitmapFilterTest::testBlurCorrectness()
 {
     // Setup test bitmap