diff --git a/toolkit/xre/nsQAppInstance.cpp b/toolkit/xre/nsQAppInstance.cpp
index 4be12c96158e..76558e63412d 100644
--- a/toolkit/xre/nsQAppInstance.cpp
+++ b/toolkit/xre/nsQAppInstance.cpp
@@ -11,6 +11,7 @@
 #include <MApplicationService>
 #endif
 #include "prenv.h"
+#include "nsXPCOMPrivate.h"
 #include <stdlib.h>
 
 QApplication *nsQAppInstance::sQAppInstance = nullptr;
@@ -29,6 +30,7 @@ void nsQAppInstance::AddRef(int& aArgc, char** aArgv, bool aDefaultProcess) {
       QApplication::setGraphicsSystem(QString(graphicsSystem));
     }
 #endif
+    mozilla::SetICUMemoryFunctions();
     sQAppInstance = new QApplication(aArgc, aArgv);
   }
   sQAppRefCount++;
diff --git a/xpcom/build/nsXPCOMPrivate.h b/xpcom/build/nsXPCOMPrivate.h
index 7f6ed3a35061..c15865a5445e 100644
--- a/xpcom/build/nsXPCOMPrivate.h
+++ b/xpcom/build/nsXPCOMPrivate.h
@@ -194,6 +194,8 @@ namespace mozilla {
 nsresult
 ShutdownXPCOM(nsIServiceManager* servMgr);
 
+void SetICUMemoryFunctions();
+
 /**
  * C++ namespaced version of NS_LogTerm.
  */
diff --git a/xpcom/build/nsXPComInit.cpp b/xpcom/build/nsXPComInit.cpp
index b314b0c080c7..3b58e19f1a71 100644
--- a/xpcom/build/nsXPComInit.cpp
+++ b/xpcom/build/nsXPComInit.cpp
@@ -554,10 +554,7 @@ NS_InitXPCOM2(nsIServiceManager* *result,
     // can't define the alloc/free functions in the JS engine, because it can't
     // depend on the XPCOM-based memory reporting goop.  So for now, we have
     // this oddness.
-    if (!JS_SetICUMemoryFunctions(ICUReporter::Alloc, ICUReporter::Realloc,
-                                  ICUReporter::Free)) {
-        NS_RUNTIMEABORT("JS_SetICUMemoryFunctions failed.");
-    }
+    mozilla::SetICUMemoryFunctions();
 
     // Initialize the JS engine.
     if (!JS_Init()) {
@@ -658,6 +655,19 @@ NS_ShutdownXPCOM(nsIServiceManager* servMgr)
 
 namespace mozilla {
 
+void
+SetICUMemoryFunctions()
+{
+    static bool sICUReporterInitialized = false;
+    if (!sICUReporterInitialized) {
+        if (!JS_SetICUMemoryFunctions(ICUReporter::Alloc, ICUReporter::Realloc,
+                                      ICUReporter::Free)) {
+            NS_RUNTIMEABORT("JS_SetICUMemoryFunctions failed.");
+        }
+        sICUReporterInitialized = true;
+    }
+}
+
 nsresult
 ShutdownXPCOM(nsIServiceManager* servMgr)
 {