diff --git a/vcl/quartz/salgdi.cxx b/vcl/quartz/salgdi.cxx
index 98b00b305366..266ec94f0b75 100644
--- a/vcl/quartz/salgdi.cxx
+++ b/vcl/quartz/salgdi.cxx
@@ -82,6 +82,10 @@ bool CoreTextGlyphFallbackSubstititution::FindFontSubstitute(vcl::font::FontSele
     CoreTextStyle* pStyle = static_cast<CoreTextStyle*>(pLogicalFont);
     CTFontRef pFont = static_cast<CTFontRef>(CFDictionaryGetValue(pStyle->GetStyleDict(), kCTFontAttributeName));
     CFStringRef pStr = CreateCFString(rMissingChars);
+    fprintf(stderr, "searching for a font that can render: <%s> :", OUStringToOString(rMissingChars, RTL_TEXTENCODING_UTF8).getStr());
+    for (int i = 0; i < rMissingChars.getLength(); ++i)
+        fprintf(stderr, " %x ", rMissingChars[i]);
+    fprintf(stderr, "\n");
     if (pStr)
     {
         CTFontRef pFallback = CTFontCreateForString(pFont, pStr, CFRangeMake(0, CFStringGetLength(pStr)));
@@ -93,6 +97,7 @@ bool CoreTextGlyphFallbackSubstititution::FindFontSubstitute(vcl::font::FontSele
             FontAttributes rAttr = DevFontFromCTFontDescriptor(pDesc, nullptr);
 
             rPattern.maSearchName = rAttr.GetFamilyName();
+            fprintf(stderr, "trying %s\n", rPattern.maSearchName.toUtf8().getStr());
 
             rPattern.SetWeight(rAttr.GetWeight());
             rPattern.SetItalic(rAttr.GetItalic());
@@ -105,6 +110,9 @@ bool CoreTextGlyphFallbackSubstititution::FindFontSubstitute(vcl::font::FontSele
         CFRelease(pStr);
     }
 
+    if (!bFound)
+        fprintf(stderr, "failed to find a candidate\n");
+
     return bFound;
 }