diff --git a/autotest/cpp/test_ogr.cpp b/autotest/cpp/test_ogr.cpp
index e6605d9f03b8..3faf8f0791b9 100644
--- a/autotest/cpp/test_ogr.cpp
+++ b/autotest/cpp/test_ogr.cpp
@@ -2483,6 +2483,36 @@ TEST_F(test_ogr, feature_defn_geomfields_iterator)
     EXPECT_EQ(i, oFDefn.GetGeomFieldCount());
 }
 
+// Test OGRGeomFieldDefn copy constructor
+TEST_F(test_ogr, geom_field_defn_copy_constructor)
+{
+    {
+        OGRGeomFieldDefn oGeomFieldDefn("field1", wkbPoint);
+        oGeomFieldDefn.SetNullable(false);
+        OGRGeomFieldDefn oGeomFieldDefn2("field2", wkbLineString);
+        oGeomFieldDefn2 = oGeomFieldDefn;
+        EXPECT_TRUE(oGeomFieldDefn2.IsSame(&oGeomFieldDefn));
+    }
+
+    {
+        OGRSpatialReference oSRS;
+        oSRS.SetFromUserInput("WGS84");
+        EXPECT_EQ(oSRS.GetReferenceCount(), 1);
+        OGRGeomFieldDefn oGeomFieldDefn("field1", wkbPoint);
+        oGeomFieldDefn.SetSpatialRef(&oSRS);
+        EXPECT_EQ(oSRS.GetReferenceCount(), 2);
+        OGRGeomFieldDefn oGeomFieldDefn2("field2", wkbLineString);
+        oGeomFieldDefn2 = oGeomFieldDefn;
+        EXPECT_EQ(oSRS.GetReferenceCount(), 3);
+        EXPECT_TRUE(oGeomFieldDefn2.IsSame(&oGeomFieldDefn));
+
+        // oGeomFieldDefn2 already points to oSRS
+        oGeomFieldDefn2 = oGeomFieldDefn;
+        EXPECT_EQ(oSRS.GetReferenceCount(), 3);
+        EXPECT_TRUE(oGeomFieldDefn2.IsSame(&oGeomFieldDefn));
+    }
+}
+
 // Test GDALDataset QueryLoggerFunc callback
 TEST_F(test_ogr, GDALDatasetSetQueryLoggerFunc)
 {
diff --git a/ogr/ogrgeomfielddefn.cpp b/ogr/ogrgeomfielddefn.cpp
index 9942cf2c8ec1..5cee03bcfcf8 100644
--- a/ogr/ogrgeomfielddefn.cpp
+++ b/ogr/ogrgeomfielddefn.cpp
@@ -157,10 +157,15 @@ OGRGeomFieldDefn &OGRGeomFieldDefn::operator=(const OGRGeomFieldDefn &oOther)
 {
     if (&oOther != this)
     {
-        SetName(oOther.pszName);
-        SetType(oOther.eGeomType);
-        SetSpatialRef(oOther.poSRS);
-        SetNullable(oOther.bNullable);
+        CPLFree(pszName);
+        pszName = CPLStrdup(oOther.pszName);
+        eGeomType = oOther.eGeomType;
+        if (oOther.poSRS)
+            const_cast<OGRSpatialReference *>(oOther.poSRS)->Reference();
+        if (poSRS)
+            const_cast<OGRSpatialReference *>(poSRS)->Dereference();
+        poSRS = oOther.poSRS;
+        bNullable = oOther.bNullable;
         m_oCoordPrecision = oOther.m_oCoordPrecision;
         m_bSealed = oOther.m_bSealed;
         bIgnore = oOther.bIgnore;