diff --git a/filter/source/msfilter/svdfppt.cxx b/filter/source/msfilter/svdfppt.cxx
index e9928a85f1e5..42f5cf81cfae 100644
--- a/filter/source/msfilter/svdfppt.cxx
+++ b/filter/source/msfilter/svdfppt.cxx
@@ -5591,7 +5591,9 @@ void PPTPortionObj::ApplyTo(  SfxItemSet& rSet, SdrPowerPointImport& rManager, T
     }
     if ( GetAttrib( PPT_CharAttr_FontHeight, nVal, nDestinationInstance ) ) // Font size in Point
     {
-        sal_uInt32 nHeight = rManager.ScalePoint( nVal );
+        constexpr sal_uInt32 MIN_FONT_HEIGHT_PT = 2;
+        sal_uInt32 nHeight = rManager.ScalePoint(std::max(nVal, MIN_FONT_HEIGHT_PT));
+
         rSet.Put( SvxFontHeightItem( nHeight, 100, EE_CHAR_FONTHEIGHT ) );
         rSet.Put( SvxFontHeightItem( nHeight, 100, EE_CHAR_FONTHEIGHT_CJK ) );
         rSet.Put( SvxFontHeightItem( nHeight, 100, EE_CHAR_FONTHEIGHT_CTL ) );
diff --git a/oox/source/export/drawingml.cxx b/oox/source/export/drawingml.cxx
index 7bbc068a7eb5..6f1a75ee9b10 100644
--- a/oox/source/export/drawingml.cxx
+++ b/oox/source/export/drawingml.cxx
@@ -2681,6 +2681,8 @@ void DrawingML::WriteRunProperties( const Reference< XPropertySet >& rRun, bool
         }
     }
 
+    assert(nSize >= 200 && "Minimum accepted value for fontsize(ST_TextFontSize) is 200");
+
     mpFS->startElementNS( XML_a, nElement,
                           XML_lang, sax_fastparser::UseIf(usLanguage, !usLanguage.isEmpty()),
                           XML_sz, OString::number(nSize),