diff --git a/gfx/src/mac/nsDeviceContextMac.cpp b/gfx/src/mac/nsDeviceContextMac.cpp
index 82acafb591a..702712ed43f 100644
--- a/gfx/src/mac/nsDeviceContextMac.cpp
+++ b/gfx/src/mac/nsDeviceContextMac.cpp
@@ -880,8 +880,9 @@ void nsDeviceContextMac :: InitFontInfoList()
 						err = ::TECConvertText(converter, &fontName[1], fontName[0], &actualInputLength, 
 													(TextPtr)unicodeFontName , sizeof(unicodeFontName), &actualOutputLength);	
 						unicodeFontName[actualOutputLength / sizeof(PRUnichar)] = '\0';
+						nsAutoString fontNameString(unicodeFontName);
 
-		        		FontNameKey key(unicodeFontName);
+		        		FontNameKey key(fontNameString);
 						gFontInfoList->Put(&key, (void*)fondID);
 					}
 					::ReleaseResource(fond);
diff --git a/gfx/src/mac/nsUnicodeFontMappingMac.cpp b/gfx/src/mac/nsUnicodeFontMappingMac.cpp
index 263240441a1..923030bfe15 100644
--- a/gfx/src/mac/nsUnicodeFontMappingMac.cpp
+++ b/gfx/src/mac/nsUnicodeFontMappingMac.cpp
@@ -312,7 +312,7 @@ nsUnicodeFontMappingMac* nsUnicodeFontMappingMac::GetCachedInstance(
 		gCache = gUtil->GetFontMappingCache();	
 
 	nsUnicodeFontMappingMac* obj = nsnull;
-	nsAutoString key = aFont->name;
+	nsAutoString key(aFont->name);
 	key.AppendWithConversion(":");
 	key.Append(aLangGroup);
 	key.AppendWithConversion(":");
diff --git a/gfx/src/nsGraphicsImpl.cpp b/gfx/src/nsGraphicsImpl.cpp
index fcb485ee407..985f9688558 100755
--- a/gfx/src/nsGraphicsImpl.cpp
+++ b/gfx/src/nsGraphicsImpl.cpp
@@ -142,7 +142,7 @@ NS_IMETHODIMP nsGraphicsImpl::DrawString(const PRUnichar *text, nscoord x, nscoo
 NS_IMETHODIMP nsGraphicsImpl::SetFont(const PRUnichar *name, nscoord size)
 {
 	size *= mDev2App;
-	nsFont font(name, NS_FONT_STYLE_NORMAL, NS_FONT_VARIANT_NORMAL, NS_FONT_WEIGHT_NORMAL, NS_FONT_DECORATION_NONE, size);
+	nsFont font(nsAutoString(name), NS_FONT_STYLE_NORMAL, NS_FONT_VARIANT_NORMAL, NS_FONT_WEIGHT_NORMAL, NS_FONT_DECORATION_NONE, size);
 	return mRenderer->SetFont(font);
 }