diff --git a/oox/source/drawingml/fillproperties.cxx b/oox/source/drawingml/fillproperties.cxx
index 9f18e7d65f7d..ff78f3183831 100644
--- a/oox/source/drawingml/fillproperties.cxx
+++ b/oox/source/drawingml/fillproperties.cxx
@@ -866,7 +866,9 @@ void GraphicProperties::pushToPropMap( PropertyMap& rPropMap, const GraphicHelpe
 
         if ( maBlipProps.moAlphaModFix.has_value() )
         {
-            rPropMap.setProperty(PROP_Transparency, static_cast<sal_Int16>(100 - (maBlipProps.moAlphaModFix.value() / PER_PERCENT)));
+            rPropMap.setProperty(
+                mbIsCustomShape ? PROP_FillTransparence : PROP_Transparency,
+                static_cast<sal_Int16>(100 - (maBlipProps.moAlphaModFix.value() / PER_PERCENT)));
         }
     }
     rPropMap.setProperty(PROP_GraphicColorMode, eColorMode);
diff --git a/sd/qa/unit/data/pptx/tdf156649.pptx b/sd/qa/unit/data/pptx/tdf156649.pptx
new file mode 100644
index 000000000000..2b3b12a9a092
Binary files /dev/null and b/sd/qa/unit/data/pptx/tdf156649.pptx differ
diff --git a/sd/qa/unit/export-tests.cxx b/sd/qa/unit/export-tests.cxx
index 61f6736fc33f..92971d4b4221 100644
--- a/sd/qa/unit/export-tests.cxx
+++ b/sd/qa/unit/export-tests.cxx
@@ -1577,6 +1577,20 @@ CPPUNIT_TEST_FIXTURE(SdExportTest, testTdf140714)
     CPPUNIT_ASSERT_EQUAL(OUString{ "com.sun.star.drawing.CustomShape" }, xShape->getShapeType());
 }
 
+CPPUNIT_TEST_FIXTURE(SdExportTest, testTdf156649)
+{
+    createSdImpressDoc("pptx/tdf156649.pptx");
+    saveAndReload("Impress Office Open XML");
+
+    auto xShapeProps(getShapeFromPage(0, 0));
+    // Without the fix in place, this test would have failed with
+    //- Expected: 55
+    //- Actual  : 0
+    // i.e. alphaModFix wasn't imported as fill transparency for the custom shape
+    CPPUNIT_ASSERT_EQUAL(sal_Int16(55),
+                         xShapeProps->getPropertyValue("FillTransparence").get<sal_Int16>());
+}
+
 CPPUNIT_TEST_FIXTURE(SdExportTest, testMasterPageBackgroundFullSize)
 {
     createSdImpressDoc("odp/background.odp");