diff --git a/source/backend/plugin/CarlaPluginThread.cpp b/source/backend/plugin/CarlaPluginThread.cpp
index 346693b12..23cf07c2e 100644
--- a/source/backend/plugin/CarlaPluginThread.cpp
+++ b/source/backend/plugin/CarlaPluginThread.cpp
@@ -85,11 +85,11 @@ void CarlaPluginThread::setOscData(const char* const binary, const char* const l
     fExtra2 = extra2;
 }
 
-ulong CarlaPluginThread::getPid() const
+uintptr_t CarlaPluginThread::getPid() const
 {
     CARLA_SAFE_ASSERT_RETURN(fProcess != nullptr, 0);
 
-    return (ulong)fProcess->pid();
+    return (uintptr_t)fProcess->pid();
 }
 
 void CarlaPluginThread::run()
diff --git a/source/backend/plugin/CarlaPluginThread.hpp b/source/backend/plugin/CarlaPluginThread.hpp
index 79565f6bb..a92e92063 100644
--- a/source/backend/plugin/CarlaPluginThread.hpp
+++ b/source/backend/plugin/CarlaPluginThread.hpp
@@ -48,7 +48,7 @@ public:
     void setMode(const CarlaPluginThread::Mode mode);
     void setOscData(const char* const binary, const char* const label, const char* const extra1="", const char* const extra2="");
 
-    ulong getPid() const;
+    uintptr_t getPid() const;
 
 protected:
     void run() override;
diff --git a/source/backend/plugin/CarlaPluginUi.cpp b/source/backend/plugin/CarlaPluginUi.cpp
index 89478f0b1..3e675c816 100644
--- a/source/backend/plugin/CarlaPluginUi.cpp
+++ b/source/backend/plugin/CarlaPluginUi.cpp
@@ -174,7 +174,7 @@ private:
 
 // -----------------------------------------------------
 
-bool CarlaPluginUi::tryTransientWinIdMatch(const ulong pid, const char* const uiTitle, const uintptr_t winId)
+bool CarlaPluginUi::tryTransientWinIdMatch(const uintptr_t pid, const char* const uiTitle, const uintptr_t winId)
 {
     CARLA_SAFE_ASSERT_RETURN(uiTitle != nullptr && uiTitle[0] != '\0', true);
     CARLA_SAFE_ASSERT_RETURN(winId != 0, true);
@@ -244,7 +244,7 @@ bool CarlaPluginUi::tryTransientWinIdMatch(const ulong pid, const char* const ui
                 CARLA_SAFE_ASSERT_CONTINUE(status == Success);
                 CARLA_SAFE_ASSERT_CONTINUE(pidSize != 0);
 
-                if (*(ulong*)pidData == pid)
+                if (*(ulong*)pidData == static_cast<ulong>(pid))
                 {
                     CARLA_SAFE_ASSERT_RETURN(lastGoodWindow == window || lastGoodWindow == 0,  true);
                     lastGoodWindow = window;
diff --git a/source/backend/plugin/CarlaPluginUi.hpp b/source/backend/plugin/CarlaPluginUi.hpp
index 0ddd0395b..6f5c69948 100644
--- a/source/backend/plugin/CarlaPluginUi.hpp
+++ b/source/backend/plugin/CarlaPluginUi.hpp
@@ -41,7 +41,7 @@ public:
     virtual void setTransientWinId(const uintptr_t winId) = 0;
     virtual void* getPtr() const noexcept = 0;
 
-    static bool tryTransientWinIdMatch(const ulong pid, const char* const uiTitle, const uintptr_t winId);
+    static bool tryTransientWinIdMatch(const uintptr_t pid, const char* const uiTitle, const uintptr_t winId);
 
 #ifdef CARLA_OS_MAC
     static CarlaPluginUi* newCocoa(CloseCallback*, uintptr_t);