--- a/js/src/jsgc.cpp
+++ b/js/src/jsgc.cpp
@@ -221,16 +221,17 @@
 #include "jit/BaselineJIT.h"
 #include "jit/IonCode.h"
 #include "jit/JitcodeMap.h"
 #include "js/SliceBudget.h"
 #include "proxy/DeadObjectProxy.h"
 #include "vm/Debugger.h"
 #include "vm/ProxyObject.h"
 #include "vm/Shape.h"
+#include "vm/SPSProfiler.h"
 #include "vm/String.h"
 #include "vm/Symbol.h"
 #include "vm/Time.h"
 #include "vm/TraceLogging.h"
 #include "vm/WrapperObject.h"
 
 #include "jsobjinlines.h"
 #include "jsscriptinlines.h"
@@ -5471,16 +5472,22 @@ GCRuntime::compactPhase(JS::gcreason::Re
                         AutoLockForExclusiveAccess& lock)
 {
     MOZ_ASSERT(rt->gc.nursery.isEmpty());
     assertBackgroundSweepingFinished();
     MOZ_ASSERT(startedCompacting);
 
     gcstats::AutoPhase ap(stats, gcstats::PHASE_COMPACT);
 
+    // TODO: JSScripts can move. If the sampler interrupts the GC in the
+    // middle of relocating an arena, invalid JSScript pointers may be
+    // accessed. Suppress all sampling until a finer-grained solution can be
+    // found. See bug 1295775.
+    AutoSuppressProfilerSampling suppressSampling(rt);
+
     while (!zonesToMaybeCompact.isEmpty()) {
         Zone* zone = zonesToMaybeCompact.front();
         MOZ_ASSERT(zone->isGCFinished());
         Arena* relocatedArenas = nullptr;
         if (relocateArenas(zone, reason, relocatedArenas, sliceBudget)) {
             zone->setGCState(Zone::Compact);
             updatePointersToRelocatedCells(zone, lock);
             zone->setGCState(Zone::Finished);