diff --git a/sc/qa/extras/macros-test.cxx b/sc/qa/extras/macros-test.cxx
index dd971e36dec1..1135fbd38f69 100644
--- a/sc/qa/extras/macros-test.cxx
+++ b/sc/qa/extras/macros-test.cxx
@@ -911,6 +911,38 @@ CPPUNIT_TEST_FIXTURE(ScMacrosTest, testTdf147122)
     CPPUNIT_ASSERT_EQUAL(Any(OUString("This is a test")), aRet);
 }
 
+CPPUNIT_TEST_FIXTURE(ScMacrosTest, testTdf154803)
+{
+    mxComponent = loadFromDesktop("private:factory/scalc");
+
+    css::uno::Reference<css::document::XEmbeddedScripts> xDocScr(mxComponent, UNO_QUERY_THROW);
+    auto xLibs = xDocScr->getBasicLibraries();
+    auto xLibrary = xLibs->createLibrary("TestLibrary");
+    xLibrary->insertByName(
+        "TestModule",
+        uno::Any(
+            OUString("Function TestExtendedMergedSelection\n"
+                     // Merge A1:B2 cell range
+                     "  oActiveSheet = ThisComponent.CurrentController.ActiveSheet\n"
+                     "  oRange = oActiveSheet.getCellRangeByName(\"A1:B2\")\n"
+                     "  ThisComponent.getCurrentController.Select(oRange)\n"
+                     "  oActiveCell = ThisComponent.CurrentSelection\n"
+                     "  oActiveCell.Merge(True)\n"
+                     // Select A1:B3 range and check for its implementation name
+                     "  oRange = oActiveSheet.getCellRangeByName(\"A1:B3\")\n"
+                     "  ThisComponent.getCurrentController.Select(oRange)\n"
+                     "  TestExtendedMergedSelection = ThisComponent.CurrentSelection.ImplementationName\n"
+                     "End Function\n")));
+
+    Any aRet = executeMacro("vnd.sun.Star.script:TestLibrary.TestModule.TestExtendedMergedSelection?"
+                            "language=Basic&location=document");
+    // Without the fix in place, this test would have failed with
+    // - Expected : ScCellRangeObj
+    // - Actual   : ScCellObj
+    // i.e. the selection was interpreted as a single cell instead of a range
+    CPPUNIT_ASSERT_EQUAL(Any(OUString("ScCellRangeObj")), aRet);
+}
+
 CPPUNIT_TEST_FIXTURE(ScMacrosTest, testTdf116127)
 {
     mxComponent = loadFromDesktop("private:factory/scalc");
diff --git a/sc/source/ui/unoobj/viewuno.cxx b/sc/source/ui/unoobj/viewuno.cxx
index 96b055250c72..bfde44272010 100644
--- a/sc/source/ui/unoobj/viewuno.cxx
+++ b/sc/source/ui/unoobj/viewuno.cxx
@@ -54,6 +54,7 @@
 #include <prevwsh.hxx>
 #include <docsh.hxx>
 #include <drwlayer.hxx>
+#include <attrib.hxx>
 #include <drawview.hxx>
 #include <fupoor.hxx>
 #include <sc.hrc>
@@ -873,13 +874,20 @@ uno::Any SAL_CALL ScTabViewObj::getSelection()
         ScMarkType eMarkType = rViewData.GetSimpleArea(aRange);
         if ( nTabs == 1 && (eMarkType == SC_MARK_SIMPLE) )
         {
-            // tdf#147122 - return cell object when a simple selection is merged
+            // tdf#154803 - check if range is entirely merged
             ScDocument& rDoc = pDocSh->GetDocument();
-            const ScPatternAttr* pMarkPattern = rDoc.GetPattern(aRange.aStart);
+            const ScMergeAttr* pMergeAttr = rDoc.GetAttr(aRange.aStart, ATTR_MERGE);
+            SCCOL nColSpan = 1;
+            SCROW nRowSpan = 1;
+            if (pMergeAttr && pMergeAttr->IsMerged())
+            {
+                nColSpan = pMergeAttr->GetColMerge();
+                nRowSpan = pMergeAttr->GetRowMerge();
+            }
+            // tdf#147122 - return cell object when a simple selection is entirely merged
             if (aRange.aStart == aRange.aEnd
-                || (pMarkPattern
-                    && pMarkPattern->GetItemSet().GetItemState(ATTR_MERGE, false)
-                           == SfxItemState::SET))
+                || (aRange.aEnd.Col() - aRange.aStart.Col() == nColSpan - 1
+                    && aRange.aEnd.Row() - aRange.aStart.Row() == nRowSpan - 1))
                 pObj = new ScCellObj( pDocSh, aRange.aStart );
             else
                 pObj = new ScCellRangeObj( pDocSh, aRange );