diff --git a/src/common/SignalVector.hpp b/src/common/SignalVector.hpp
index 3bbd4fc6..98253e45 100644
--- a/src/common/SignalVector.hpp
+++ b/src/common/SignalVector.hpp
@@ -62,9 +62,10 @@ class BaseSignalVector : public ReadOnlySignalVector<TVectorItem>
 {
 public:
     // returns the actual index of the inserted item
-    virtual int insertItem(const TVectorItem &item, int proposedIndex = -1, void *caller = 0) = 0;
+    virtual int insertItem(const TVectorItem &item, int proposedIndex = -1,
+                           void *caller = nullptr) = 0;
 
-    void removeItem(int index, void *caller = 0)
+    void removeItem(int index, void *caller = nullptr)
     {
         assertInGuiThread();
         assert(index >= 0 && index < this->vector.size());
@@ -77,7 +78,7 @@ public:
         this->invokeDelayedItemsChanged();
     }
 
-    int appendItem(const TVectorItem &item, void *caller = 0)
+    int appendItem(const TVectorItem &item, void *caller = nullptr)
     {
         return this->insertItem(item, -1, caller);
     }
@@ -87,7 +88,7 @@ template <typename TVectorItem>
 class UnsortedSignalVector : public BaseSignalVector<TVectorItem>
 {
 public:
-    virtual int insertItem(const TVectorItem &item, int index = -1, void *caller = 0) override
+    virtual int insertItem(const TVectorItem &item, int index = -1, void *caller = nullptr) override
     {
         assertInGuiThread();
         if (index == -1) {