diff --git a/src/widgets/itemviews/qheaderview.cpp b/src/widgets/itemviews/qheaderview.cpp
index 32dac19036d..64098d91710 100644
--- a/src/widgets/itemviews/qheaderview.cpp
+++ b/src/widgets/itemviews/qheaderview.cpp
@@ -135,10 +135,11 @@ static const int maxSizeSection = 1048575; // since section size is in a bitfiel
     or more sections are resized or reordered. This means that it's possible
     for a model to have millions of sections without QHeaderView consuming a proportional,
     and therefore huge, amount of memory, as long as there are \e no calls to
-    \l swapSections, \l resizeSection, \l hideSection, \moveSection and \l stretchLastSection
-    (enabling it).
-    In order to avoid such calls by user actions the  \l resizeMode
-    should be fixed for all sections and the user should be prevented from
+    \l swapSections, \l resizeSection, \l hideSection, \l moveSection,
+    and \l stretchLastSection (enabling it).
+    In order to avoid such calls by user actions the \l resizeMode
+    should be fixed (without specifying it for any indexes as
+    that will do the opposite). The user should also be prevented from
     moving sections by keeping \l sectionsMovable disabled.
 */
 
@@ -4074,6 +4075,10 @@ int QHeaderViewPrivate::headerVisualIndexAt(int position) const
 
 void QHeaderViewPrivate::setHeaderSectionResizeMode(int visual, QHeaderView::ResizeMode mode)
 {
+    if (visual < 0)
+        return;
+    if (noSectionMemoryUsage())
+        switchToFlexibleModeWithSectionMemoryUsage();
     int size = headerSectionSize(visual);
     createSectionItems(visual, visual, size, mode);
 }
diff --git a/tests/auto/widgets/itemviews/qheaderview/tst_qheaderview.cpp b/tests/auto/widgets/itemviews/qheaderview/tst_qheaderview.cpp
index c666f41868d..62e0370b892 100644
--- a/tests/auto/widgets/itemviews/qheaderview/tst_qheaderview.cpp
+++ b/tests/auto/widgets/itemviews/qheaderview/tst_qheaderview.cpp
@@ -236,6 +236,7 @@ private slots:
     void normalMemoryUsageOnResize();
     void normalMemoryUsageOnHide();
     void storeRestoreLowMemoryMode();
+    void setSectionResizeModeWithSectionWillTakeMemory();
 
 protected:
     void setupTestData(bool use_reset_model = false);
@@ -3804,6 +3805,19 @@ void tst_QHeaderView::lowMememoryUsageOnSetDefaultSectionSize()
     QVERIFY(tv.hasLowMemoryUsage());
 }
 
+void tst_QHeaderView::setSectionResizeModeWithSectionWillTakeMemory()
+{
+    // The global default is only a default for new sections
+    // (and working fine in no memory usage mode when it hasn't been specified)
+    // A (forced) resize mode on a section requires memory for keeping the information.
+    TableViewWithBasicModel tv1;
+    tv1.header->setSectionResizeMode(3, QHeaderView::Fixed);
+    QVERIFY(!tv1.hasLowMemoryUsage());
+
+    TableViewWithBasicModel tv2;
+    tv2.header->setSectionResizeMode(500, QHeaderView::Interactive);
+    QVERIFY(!tv2.hasLowMemoryUsage());
+}
 
 QTEST_MAIN(tst_QHeaderView)
 #include "tst_qheaderview.moc"