--- a/toolkit/crashreporter/nsExceptionHandler.cpp
+++ b/toolkit/crashreporter/nsExceptionHandler.cpp
@@ -481,16 +481,20 @@ bool SimpleNoCLibDtoA(double aValue, cha
     }
     aBuffer[i] = '\0';
   }
   return ok;
 }
 
 namespace CrashReporter {
 
+#if defined(XP_LINUX) || defined(XP_WIN32)
+static bool sIncludeHeapRegions = false;
+#endif
+
 #ifdef XP_LINUX
 inline void
 my_inttostring(intmax_t t, char* buffer, size_t buffer_length)
 {
   my_memset(buffer, 0, buffer_length);
   my_uitos(buffer, t, my_uint_len(t));
 }
 #endif
@@ -2354,16 +2358,21 @@ nsresult UnregisterAppMemory(void* ptr)
 #if defined(XP_LINUX) || defined(XP_WIN32)
   gExceptionHandler->UnregisterAppMemory(ptr);
   return NS_OK;
 #else
   return NS_ERROR_NOT_IMPLEMENTED;
 #endif
 }
 
+void SetIncludeHeapRegions(bool aEnabled)
+{
+  sIncludeHeapRegions = aEnabled;
+}
+
 bool GetServerURL(nsACString& aServerURL)
 {
   if (!gExceptionHandler)
     return false;
 
   return GetAnnotation(NS_LITERAL_CSTRING("ServerURL"), aServerURL);
 }
 

--- a/toolkit/crashreporter/nsExceptionHandler.h
+++ b/toolkit/crashreporter/nsExceptionHandler.h
@@ -89,16 +89,19 @@ nsresult SetRestartArgs(int argc, char**
 nsresult SetupExtraData(nsIFile* aAppDataDirectory,
                         const nsACString& aBuildID);
 bool GetLastRunCrashID(nsAString& id);
 
 // Registers an additional memory region to be included in the minidump
 nsresult RegisterAppMemory(void* ptr, size_t length);
 nsresult UnregisterAppMemory(void* ptr);
 
+// Enable or disable inclusion of heap regions in the minidump.
+void SetIncludeHeapRegions(bool aEnabled);
+
 // Functions for working with minidumps and .extras
 typedef nsDataHashtable<nsCStringHashKey, nsCString> AnnotationTable;
 
 void DeleteMinidumpFilesForID(const nsAString& id);
 bool GetMinidumpForID(const nsAString& id, nsIFile** minidump);
 bool GetIDFromMinidump(nsIFile* minidump, nsAString& id);
 bool GetExtraFileForID(const nsAString& id, nsIFile** extraFile);
 bool GetExtraFileForMinidump(nsIFile* minidump, nsIFile** extraFile);

--- a/toolkit/xre/nsAppRunner.cpp
+++ b/toolkit/xre/nsAppRunner.cpp
@@ -4252,16 +4252,26 @@ XREMain::XRE_mainRun()
   nsCString userAgentLocale;
   // Try a localized string first. This pref is always a localized string in
   // Fennec, and might be elsewhere, too.
   if (NS_SUCCEEDED(Preferences::GetLocalizedCString("general.useragent.locale", &userAgentLocale))) {
     CrashReporter::AnnotateCrashReport(NS_LITERAL_CSTRING("useragent_locale"), userAgentLocale);
   } else if (NS_SUCCEEDED(Preferences::GetCString("general.useragent.locale", &userAgentLocale))) {
     CrashReporter::AnnotateCrashReport(NS_LITERAL_CSTRING("useragent_locale"), userAgentLocale);
   }
+
+#if defined(XP_WIN) || defined(XP_LINUX)
+    bool includeHeapRegions =
+#ifndef RELEASE_BUILD
+      true || // Include heap regions on nightly and aurora by default.
+#endif
+      Preferences::GetBool("toolkit.crashreporter.includeHeapRegions", false);
+    CrashReporter::SetIncludeHeapRegions(includeHeapRegions);
+#endif
+
 #endif
 
   appStartup->GetShuttingDown(&mShuttingDown);
 
   nsCOMPtr<nsICommandLineRunner> cmdLine;
 
   nsCOMPtr<nsIFile> workingDir;
   rv = NS_GetSpecialDirectory(NS_OS_CURRENT_WORKING_DIR, getter_AddRefs(workingDir));