diff --git a/modules/juce_core/native/juce_linux_Files.cpp b/modules/juce_core/native/juce_linux_Files.cpp
index 02b3b36a68..7cc17d2684 100644
--- a/modules/juce_core/native/juce_linux_Files.cpp
+++ b/modules/juce_core/native/juce_linux_Files.cpp
@@ -129,8 +129,8 @@ File File::getLinkedTarget() const
 }
 
 //==============================================================================
-extern const char** juce_argv;  // declared in juce_Application.cpp
-extern int juce_argc;
+const char* const* juce_argv = nullptr;
+int juce_argc = 0;
 
 File File::getSpecialLocation (const SpecialLocationType type)
 {
diff --git a/modules/juce_core/native/juce_mac_Files.mm b/modules/juce_core/native/juce_mac_Files.mm
index 6ceb94c859..c7bb9bbc48 100644
--- a/modules/juce_core/native/juce_mac_Files.mm
+++ b/modules/juce_core/native/juce_mac_Files.mm
@@ -163,8 +163,8 @@ bool File::isHidden() const
 }
 
 //==============================================================================
-extern const char** juce_argv;  // declared in juce_Application.cpp
-extern int juce_argc;
+const char* const* juce_argv = nullptr;
+int juce_argc = 0;
 
 File File::getSpecialLocation (const SpecialLocationType type)
 {
diff --git a/modules/juce_gui_basics/application/juce_Application.cpp b/modules/juce_gui_basics/application/juce_Application.cpp
index b9dc78d980..2c812cab84 100644
--- a/modules/juce_gui_basics/application/juce_Application.cpp
+++ b/modules/juce_gui_basics/application/juce_Application.cpp
@@ -225,8 +225,8 @@ int JUCEApplication::main()
  extern void initialiseNSApplication();
 #endif
 
-const char* const* juce_argv = nullptr;
-int juce_argc = 0;
+extern const char** juce_argv;  // declared in juce_core
+extern int juce_argc;
 
 StringArray JUCEApplication::getCommandLineParameterArray()
 {
diff --git a/modules/juce_gui_basics/menus/juce_PopupMenu.cpp b/modules/juce_gui_basics/menus/juce_PopupMenu.cpp
index b2e4f867cb..5ed1bce3dc 100644
--- a/modules/juce_gui_basics/menus/juce_PopupMenu.cpp
+++ b/modules/juce_gui_basics/menus/juce_PopupMenu.cpp
@@ -394,7 +394,7 @@ public:
                 Component::SafePointer<Window> parentWindow (owner);
                 PopupMenu::ItemComponent* currentChildOfParent = parentWindow->currentChild;
 
-                hide (0, true);
+                hide (nullptr, true);
 
                 if (parentWindow != nullptr)
                     parentWindow->setCurrentlyHighlightedChild (currentChildOfParent);
@@ -520,7 +520,7 @@ public:
         }
 
         if (hideOnExit && hasBeenOver && ! isOverAny)
-            hide (0, true);
+            hide (nullptr, true);
         else
             checkButtonState (localMousePos, timeNow, wasDown, overScrollArea, isOverAny);
     }
@@ -999,7 +999,7 @@ private:
                       && (isOver || (activeSubMenu == nullptr) || ! activeSubMenu->isVisible()))
                 {
                     if (isOver && (c != nullptr) && (activeSubMenu != nullptr))
-                        activeSubMenu->hide (0, true);
+                        activeSubMenu->hide (nullptr, true);
 
                     if (! isOver)
                         itemUnderMouse = nullptr;
@@ -1413,7 +1413,7 @@ public:
     PopupMenuCompletionCallback()
         : managerOfChosenCommand (nullptr),
           prevFocused (Component::getCurrentlyFocusedComponent()),
-          prevTopLevel (prevFocused != nullptr ? prevFocused->getTopLevelComponent() : 0)
+          prevTopLevel (prevFocused != nullptr ? prevFocused->getTopLevelComponent() : nullptr)
     {
         PopupMenuSettings::menuWasHiddenBecauseOfAppChange = false;
     }