diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 8e57a111..6f92d617 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -13,10 +13,9 @@ jobs:
     strategy:
       matrix:
         os:
-          # wrong use of AU MIDIPacket
-          # - macos-12
-          # - macos-13
-          # - macos-14
+          - macos-13
+          - macos-14
+          - macos-15
           # webgui failure
           # - ubuntu-20.04
           - ubuntu-22.04
diff --git a/.github/workflows/cmake.yml b/.github/workflows/cmake.yml
index 4202a693..5bdbbced 100644
--- a/.github/workflows/cmake.yml
+++ b/.github/workflows/cmake.yml
@@ -42,11 +42,11 @@ jobs:
           suffix: _24_04
           target: ${{ matrix.target }}
 
-  macos-12:
+  macos-13:
     strategy:
       matrix:
         target: [macos-intel, macos-universal, macos-10.15]
-    runs-on: macos-12
+    runs-on: macos-13
     steps:
       - uses: actions/checkout@v4
         with:
@@ -54,14 +54,14 @@ jobs:
       - uses: distrho/dpf-cmake-action@v1
         with:
           dpf_path: .
-          suffix: _12
+          suffix: _13
           target: ${{ matrix.target }}
 
-  macos-13:
+  macos-14:
     strategy:
       matrix:
         target: [macos-intel, macos-universal, macos-10.15]
-    runs-on: macos-13
+    runs-on: macos-14
     steps:
       - uses: actions/checkout@v4
         with:
@@ -69,14 +69,14 @@ jobs:
       - uses: distrho/dpf-cmake-action@v1
         with:
           dpf_path: .
-          suffix: _13
+          suffix: _14
           target: ${{ matrix.target }}
 
-  macos-14:
+  macos-15:
     strategy:
       matrix:
         target: [macos-intel, macos-universal, macos-10.15]
-    runs-on: macos-14
+    runs-on: macos-15
     steps:
       - uses: actions/checkout@v4
         with:
@@ -84,7 +84,7 @@ jobs:
       - uses: distrho/dpf-cmake-action@v1
         with:
           dpf_path: .
-          suffix: _14
+          suffix: _15
           target: ${{ matrix.target }}
 
   cmake_win32:
diff --git a/.github/workflows/example-plugins.yml b/.github/workflows/example-plugins.yml
index 8ac77fcc..86bd43e0 100644
--- a/.github/workflows/example-plugins.yml
+++ b/.github/workflows/example-plugins.yml
@@ -39,11 +39,11 @@ jobs:
           suffix: _24_04
           target: ${{ matrix.target }}
 
-  macos-12:
+  macos-13:
     strategy:
       matrix:
         target: [macos-intel, macos-universal, macos-10.15]
-    runs-on: macos-12
+    runs-on: macos-13
     steps:
       - uses: actions/checkout@v4
         with:
@@ -51,14 +51,14 @@ jobs:
       - uses: distrho/dpf-makefile-action@v1
         with:
           dpf_path: .
-          suffix: _12
+          suffix: _13
           target: ${{ matrix.target }}
 
-  macos-13:
+  macos-14:
     strategy:
       matrix:
         target: [macos-intel, macos-universal, macos-10.15]
-    runs-on: macos-13
+    runs-on: macos-14
     steps:
       - uses: actions/checkout@v4
         with:
@@ -66,14 +66,14 @@ jobs:
       - uses: distrho/dpf-makefile-action@v1
         with:
           dpf_path: .
-          suffix: _13
+          suffix: _14
           target: ${{ matrix.target }}
 
-  macos-14:
+  macos-15:
     strategy:
       matrix:
         target: [macos-intel, macos-universal, macos-10.15]
-    runs-on: macos-14
+    runs-on: macos-15
     steps:
       - uses: actions/checkout@v4
         with:
@@ -81,5 +81,5 @@ jobs:
       - uses: distrho/dpf-makefile-action@v1
         with:
           dpf_path: .
-          suffix: _14
+          suffix: _15
           target: ${{ matrix.target }}
diff --git a/distrho/extra/WebViewImpl.cpp b/distrho/extra/WebViewImpl.cpp
index cea63578..7b6df4eb 100644
--- a/distrho/extra/WebViewImpl.cpp
+++ b/distrho/extra/WebViewImpl.cpp
@@ -106,7 +106,7 @@
 
 @implementation WEB_VIEW_DELEGATE_CLASS_NAME {
 @public
-    WebViewMessageCallback callback;
+    DISTRHO_NAMESPACE::WebViewMessageCallback callback;
     void* callbackPtr;
     bool loaded;
 }
diff --git a/distrho/src/DistrhoPluginAU.cpp b/distrho/src/DistrhoPluginAU.cpp
index 863a4744..96b90f78 100644
--- a/distrho/src/DistrhoPluginAU.cpp
+++ b/distrho/src/DistrhoPluginAU.cpp
@@ -202,7 +202,8 @@ static constexpr const uint32_t kType = d_cconst(STRINGIFY(DISTRHO_PLUGIN_AU_TYP
 static constexpr const uint32_t kSubType = d_cconst(STRINGIFY(DISTRHO_PLUGIN_UNIQUE_ID));
 static constexpr const uint32_t kManufacturer = d_cconst(STRINGIFY(DISTRHO_PLUGIN_BRAND_ID));
 
-static constexpr const uint32_t kWantedAudioFormat = kAudioFormatFlagsNativeFloatPacked
+static constexpr const uint32_t kWantedAudioFormat = 0
+                                                   | kAudioFormatFlagsNativeFloatPacked
                                                    | kAudioFormatFlagIsNonInterleaved;
 
 
@@ -278,8 +279,18 @@ typedef std::vector<RenderListener> RenderListeners;
 
 #if DISTRHO_PLUGIN_WANT_MIDI_OUTPUT
 // useful definitions
-static constexpr const uint32_t kMIDIPacketNonDataSize = sizeof(MIDIPacket) - sizeof(MIDIPacket::data);
-static constexpr const uint32_t kMIDIPacketListNonDataSize = sizeof(MIDIPacketList) - sizeof(MIDIPacketList::packet);
+static constexpr const uint32_t kMIDIPacketNonDataSize = sizeof(MIDIPacket)
+                                                      #if __cplusplus >= 201103L
+                                                       - sizeof(MIDIPacket::data);
+                                                      #else
+                                                       - sizeof(static_cast<MIDIPacket*>(0)->data);
+                                                      #endif
+static constexpr const uint32_t kMIDIPacketListNonDataSize = sizeof(MIDIPacketList)
+                                                          #if __cplusplus >= 201103L
+                                                           - sizeof(MIDIPacketList::packet);
+                                                          #else
+                                                           - sizeof(static_cast<MIDIPacketList*>(0)->packet);
+                                                          #endif
 
 // size of data used for midi events
 static constexpr const uint32_t kMIDIPacketListMaxDataSize = kMIDIPacketNonDataSize * kMaxMidiEvents
diff --git a/distrho/src/DistrhoUIAU.mm b/distrho/src/DistrhoUIAU.mm
index c0987f51..1b3f77e5 100644
--- a/distrho/src/DistrhoUIAU.mm
+++ b/distrho/src/DistrhoUIAU.mm
@@ -387,6 +387,9 @@ END_NAMESPACE_DISTRHO
 #define COCOA_VIEW_CLASS_NAME \
     MACRO_NAME(CocoaView_, DISTRHO_PLUGIN_AU_TYPE, _, DISTRHO_PLUGIN_UNIQUE_ID, _, DISTRHO_PLUGIN_BRAND_ID)
 
+using DISTRHO_NAMESPACE::DPF_UI_AU;
+using DISTRHO_NAMESPACE::d_nextSampleRate;
+
 @interface COCOA_VIEW_CLASS_NAME : NSView
 {
 @public
diff --git a/distrho/src/DistrhoUIInternal.hpp b/distrho/src/DistrhoUIInternal.hpp
index e9ae05c5..ea3f56a2 100644
--- a/distrho/src/DistrhoUIInternal.hpp
+++ b/distrho/src/DistrhoUIInternal.hpp
@@ -267,12 +267,12 @@ public:
         uiData->app.repaintIfNeeeded();
     }
 
-    void addIdleCallbackForNativeIdle(IdleCallback* const cb, const uint timerFrequencyInMs)
+    void addIdleCallbackForNativeIdle(DGL_NAMESPACE::IdleCallback* const cb, const uint timerFrequencyInMs)
     {
         uiData->window->addIdleCallback(cb, timerFrequencyInMs);
     }
 
-    void removeIdleCallbackForNativeIdle(IdleCallback* const cb)
+    void removeIdleCallbackForNativeIdle(DGL_NAMESPACE::IdleCallback* const cb)
     {
         uiData->window->removeIdleCallback(cb);
     }
diff --git a/distrho/src/DistrhoUIVST3.cpp b/distrho/src/DistrhoUIVST3.cpp
index 0ecf675f..a326c4b3 100644
--- a/distrho/src/DistrhoUIVST3.cpp
+++ b/distrho/src/DistrhoUIVST3.cpp
@@ -129,7 +129,7 @@ static uint translateVST3Modifiers(const int64_t modifiers) noexcept
  * Helper class for getting a native idle timer.
  */
 #if !DPF_VST3_USING_HOST_RUN_LOOP
-class NativeIdleCallback : public IdleCallback
+class NativeIdleCallback : public DGL_NAMESPACE::IdleCallback
 {
 public:
     NativeIdleCallback(UIExporter& ui)