--- a/js/src/devtools/rootAnalysis/analyzeHeapWrites.js
+++ b/js/src/devtools/rootAnalysis/analyzeHeapWrites.js
@@ -408,16 +408,20 @@ function ignoreContents(entry)
         "Gecko_CSSValue_SetArray",
         "Gecko_CSSValue_InitSharedList",
         "Gecko_EnsureMozBorderColors",
         "Gecko_ClearMozBorderColors",
         "Gecko_AppendMozBorderColors",
         "Gecko_CopyMozBorderColors",
         "Gecko_SetNullImageValue",
 
+        // The analysis thinks we'll write to mBits in the DoGetStyleFoo<false>
+        // call.  Maybe the template parameter confuses it?
+        /nsStyleContext::PeekStyle/,
+
         // Needs main thread assertions or other fixes.
         /UndisplayedMap::GetEntryFor/,
         /nsStyleContext::CalcStyleDifferenceInternal/,
         /EffectCompositor::GetServoAnimationRule/,
         /LookAndFeel::GetColor/,
         "Gecko_CopyStyleContentsFrom",
         "Gecko_CSSValue_SetAbsoluteLength",
         "Gecko_UnsetDirtyStyleAttr",