diff --git a/dom/html/crashtests/crashtests.list b/dom/html/crashtests/crashtests.list
index 6ef539a648bd..30f74245330e 100644
--- a/dom/html/crashtests/crashtests.list
+++ b/dom/html/crashtests/crashtests.list
@@ -51,7 +51,7 @@ load 680922-1.xul
 load 682058.xhtml
 load 682460.html
 load 738744.xhtml
-asserts-if(stylo,6-30) load 741218.json # bug 1324634
+load 741218.json
 load 741250.xhtml
 load 795221-1.html
 asserts-if(stylo,1) load 795221-2.html # bug 1324702
diff --git a/dom/jsurl/crashtests/crashtests.list b/dom/jsurl/crashtests/crashtests.list
index b098d6f4fd73..73c36b6ac51d 100644
--- a/dom/jsurl/crashtests/crashtests.list
+++ b/dom/jsurl/crashtests/crashtests.list
@@ -1,6 +1,6 @@
 load 341963-1.html
 load 344874-1.html
 load 344996-1.xhtml
-asserts-if(stylo,4) load 457050-1.html # bug 1324634
+load 457050-1.html
 load 1018583.html
 load 1180389.html
diff --git a/layout/generic/crashtests/crashtests.list b/layout/generic/crashtests/crashtests.list
index 5a2feff85f4a..c349f9684cd9 100644
--- a/layout/generic/crashtests/crashtests.list
+++ b/layout/generic/crashtests/crashtests.list
@@ -458,7 +458,7 @@ load 655462-1.html
 load 656130-1.html
 load 656130-2.html
 load 660416.html
-asserts-if(stylo,2) load 665853.html # bug 1324634
+load 665853.html
 load 667025.html
 skip-if(stylo) load 673770.html # bug 1323652
 load 679933-1.html
diff --git a/layout/style/Loader.cpp b/layout/style/Loader.cpp
index fbf566da156a..baa759e29d89 100644
--- a/layout/style/Loader.cpp
+++ b/layout/style/Loader.cpp
@@ -57,6 +57,7 @@
 #include "mozilla/StyleSheet.h"
 #include "mozilla/StyleSheetInlines.h"
 #include "mozilla/ConsoleReportCollector.h"
+#include "mozilla/ServoUtils.h"
 
 #ifdef MOZ_XUL
 #include "nsXULPrototypeCache.h"
@@ -1877,9 +1878,11 @@ Loader::DoSheetComplete(SheetLoadData* aLoadData, nsresult aStatus,
                                          aLoadData->mSheet->GetReferrerPolicy());
 #ifdef DEBUG
       SheetLoadData *loadingData;
-      NS_ASSERTION(mSheets->mLoadingDatas.Get(&key, &loadingData) &&
-                   loadingData == aLoadData,
-                   "Bad loading table");
+      // XXXheycam Temporarily downgrade this assertion (bug 1314045).
+      NS_ASSERTION_STYLO_WARNING(
+        mSheets->mLoadingDatas.Get(&key, &loadingData) &&
+        loadingData == aLoadData,
+        "Bad loading table");
 #endif
 
       mSheets->mLoadingDatas.Remove(&key);
diff --git a/layout/style/ServoUtils.h b/layout/style/ServoUtils.h
index b116b9c4f461..875113992034 100644
--- a/layout/style/ServoUtils.h
+++ b/layout/style/ServoUtils.h
@@ -79,4 +79,11 @@
 #define MOZ_STYLO_FORWARD(method_, args_) \
   MOZ_STYLO_FORWARD_CONCRETE(method_, args_, args_)
 
+// Warning in MOZ_STYLO builds and non-fatally assert in regular builds.
+#ifdef MOZ_STYLO
+#define NS_ASSERTION_STYLO_WARNING(...) NS_WARNING_ASSERTION(__VA_ARGS__)
+#else
+#define NS_ASSERTION_STYLO_WARNING(...) NS_ASSERTION(__VA_ARGS__)
+#endif
+
 #endif // mozilla_ServoUtils_h
diff --git a/layout/style/crashtests/crashtests.list b/layout/style/crashtests/crashtests.list
index e670c627c5b3..2e4bba54ea10 100644
--- a/layout/style/crashtests/crashtests.list
+++ b/layout/style/crashtests/crashtests.list
@@ -18,7 +18,7 @@ asserts-if(stylo,1) load 397022-1.html # bug 1324704
 load 399289-1.svg
 load 404470-1.html
 load 411603-1.html
-asserts-if(stylo,2) load 412588-1.html # bug 1324634
+load 412588-1.html
 load 413274-1.xhtml
 load 416461-1.xul
 load 418007-1.xhtml
@@ -37,7 +37,7 @@ load 452150-1.xhtml
 skip-if(stylo) load 456196.html # bug 132652
 load 460209-1.html
 load 460217-1.html
-asserts-if(stylo,2) load 460323-1.html # bug 1324634
+load 460323-1.html
 load 466845-1.html
 load 469432-1.xhtml
 load 472195-1.html
@@ -48,8 +48,8 @@ load 473892-1.html
 load 473914-1.html
 load 474377-1.xhtml
 load 478321-1.xhtml
-asserts-if(stylo,3) load 495269-1.html # bug 1324634
-asserts-if(stylo,3) load 495269-2.html # bug 1324634
+load 495269-1.html
+load 495269-2.html
 load 498036-1.html
 load 509155-1.html
 load 509156-1.html
@@ -68,7 +68,7 @@ load 580685.html
 load 585185-1.html
 load 588627-1.html
 load 592698-1.html
-asserts-if(stylo,2) load 601437-1.html # bug 1324634
+load 601437-1.html
 load 601439-1.html
 load 605689-1.html
 load 611922-1.html
@@ -100,7 +100,7 @@ load 840898.html
 load 842134.html
 load 861489-1.html
 load 862113.html
-asserts-if(stylo,5) load 867487.html # bug 1324634
+load 867487.html
 load 873222.html
 asserts-if(stylo,2) load 880862.html # bug 1324701
 load 894245-1.html
diff --git a/netwerk/test/crashtests/crashtests.list b/netwerk/test/crashtests/crashtests.list
index 641f61137e91..b90efc5fb2b9 100644
--- a/netwerk/test/crashtests/crashtests.list
+++ b/netwerk/test/crashtests/crashtests.list
@@ -1,3 +1,3 @@
-asserts-if(stylo,4) load 785753-1.html # bug 1324634
-asserts-if(stylo,4) load 785753-2.html # bug 1324634
+load 785753-1.html
+load 785753-2.html
 load 1274044-1.html
diff --git a/parser/htmlparser/tests/crashtests/crashtests.list b/parser/htmlparser/tests/crashtests/crashtests.list
index 9e4b389eabd6..d026eb595c32 100644
--- a/parser/htmlparser/tests/crashtests/crashtests.list
+++ b/parser/htmlparser/tests/crashtests/crashtests.list
@@ -1,6 +1,6 @@
 load 30885-1.html
 load 30956-1.html
-asserts-if(stylo,2) load 31392-1.html # bug 1324634
+load 31392-1.html
 load 31694-1.html
 load 31940-1.html
 load 32613-1.html