diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 19fd7f2..875c12a 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -32,6 +32,25 @@ jobs:
       - name: Show toolchain
         run: xcodebuild -version && swift --version
 
+      # Package.swift は `../ios-sdk-core` があればそれを使い、無ければ released 版
+      # （`from: "1.1.4"`）へ解決する。CI はこのリポジトリしか checkout しないので
+      # 常に released 版になり、**コアの未リリースな変更に追随する PR は永久に赤いまま**
+      # になっていた（CameraBearing をコアへ足したときに踏んだ）。
+      # 隣に置いてローカル開発と同じ経路に乗せる。同名ブランチがあればそちらを使う。
+      - name: Check out MapConductorCore next to this package
+        env:
+          HEAD_REF: ${{ github.head_ref }}
+        run: |
+          url=https://github.com/MapConductor/ios-sdk-core.git
+          if [ -n "$HEAD_REF" ] && git ls-remote --exit-code --heads "$url" "$HEAD_REF" >/dev/null 2>&1; then
+            echo "ios-sdk-core: matching branch $HEAD_REF"
+            git clone --depth 1 --branch "$HEAD_REF" "$url" ../ios-sdk-core
+          else
+            echo "ios-sdk-core: default branch"
+            git clone --depth 1 "$url" ../ios-sdk-core
+          fi
+          test -f ../ios-sdk-core/Package.swift
+
       - name: Build
         run: |
           scheme=$(sed -n 's/^[[:space:]]*name: "\([^"]*\)".*/\1/p' Package.swift | head -1)
diff --git a/Sources/MapConductorForMapKit/MapCameraPositionExtensions.swift b/Sources/MapConductorForMapKit/MapCameraPositionExtensions.swift
index e39a96c..b740503 100644
--- a/Sources/MapConductorForMapKit/MapCameraPositionExtensions.swift
+++ b/Sources/MapConductorForMapKit/MapCameraPositionExtensions.swift
@@ -1,6 +1,6 @@
 import Foundation
 import MapKit
-import MapConductorCore
+@_spi(MapConductorDriver) import MapConductorCore
 
 private let converter = MapKitZoomAltitudeConverter(zoom0Altitude: 171_319_879.0)
 private let mapKitMaxPitch: Double = 80.9
@@ -30,7 +30,7 @@ public extension MapCameraPosition {
             ? Spherical.computeOffset(
                 origin: position,
                 distance: distance * tan(pitchRadians),
-                heading: bearing
+                heading: CameraBearing.toNativeHeading(bearing)
             )
             : position
 
@@ -42,7 +42,7 @@ public extension MapCameraPosition {
             ),
             fromDistance: distance,
             pitch: nativePitch,
-            heading: bearing
+            heading: CameraBearing.toNativeHeading(bearing)
         )
     }
 }
@@ -54,7 +54,11 @@ public extension MKMapView {
         visibleRegion: VisibleRegion? = nil
     ) -> MapCameraPosition {
         let cameraAltitude = camera.altitude
-        let pitchRadians = camera.pitch * .pi / 180.0
+        // `MKMapCamera.pitch` は CGFloat。CGFloat と Double の暗黙変換に任せると
+        // CoreGraphics の `cos(CGFloat)` と Foundation の `cos(Double)` が両方候補になり、
+        // ツールチェーンによっては `ambiguous use of 'cos'` で落ちる（CI の macos-15 で踏んだ）。
+        // 手元の Xcode では通ってしまうので、Double へ明示的に寄せておく。
+        let pitchRadians = Double(camera.pitch) * .pi / 180.0
         // Recover the slant distance set via MKMapCamera(fromDistance:) — the inverse of toMKMapCamera().
         let slantDistance = cameraAltitude / max(cos(pitchRadians), minCosTilt)
         var position = GeoPoint(
@@ -95,7 +99,7 @@ public extension MKMapView {
         return MapCameraPosition(
             position: position,
             zoom: zoom,
-            bearing: camera.heading,
+            bearing: CameraBearing.bearingFromNativeHeading(camera.heading),
             tilt: logicalTilt,
             visibleRegion: visibleRegion
         )
@@ -154,7 +158,11 @@ private extension MKMapView {
     /// from whatever camera happens to be set and reused to place the next one.
     func metersPerPointPerDistance() -> Double? {
         guard let metersPerPoint = measuredMetersPerPointAtCenter() else { return nil }
-        let pitchRadians = camera.pitch * .pi / 180.0
+        // `MKMapCamera.pitch` は CGFloat。CGFloat と Double の暗黙変換に任せると
+        // CoreGraphics の `cos(CGFloat)` と Foundation の `cos(Double)` が両方候補になり、
+        // ツールチェーンによっては `ambiguous use of 'cos'` で落ちる（CI の macos-15 で踏んだ）。
+        // 手元の Xcode では通ってしまうので、Double へ明示的に寄せておく。
+        let pitchRadians = Double(camera.pitch) * .pi / 180.0
         let slantDistance = camera.altitude / max(cos(pitchRadians), minCosTilt)
         guard slantDistance > 0 else { return nil }
         let factor = metersPerPoint / slantDistance
diff --git a/Sources/MapConductorForMapKit/controller/MapKitViewController.swift b/Sources/MapConductorForMapKit/controller/MapKitViewController.swift
index dbb0f02..02bdbea 100644
--- a/Sources/MapConductorForMapKit/controller/MapKitViewController.swift
+++ b/Sources/MapConductorForMapKit/controller/MapKitViewController.swift
@@ -1,7 +1,7 @@
 import Foundation
 import CoreLocation
 import MapKit
-import MapConductorCore
+@_spi(MapConductorDriver) import MapConductorCore
 import QuartzCore
 import UIKit
 
@@ -228,12 +228,12 @@ final class MapKitViewController: MapViewControllerProtocol {
             // Use UIView.animate to respect the specified duration
             UIView.animate(withDuration: duration) {
                 mapView.setVisibleMapRect(rect, edgePadding: .zero, animated: false)
-                Self.applyHeading(position.bearing, center: centerCoordinate, to: mapView, animated: false)
+                Self.applyHeading(CameraBearing.toNativeHeading(position.bearing), center: centerCoordinate, to: mapView, animated: false)
             }
         } else {
             // Use MapKit's default animation or no animation
             mapView.setVisibleMapRect(rect, edgePadding: .zero, animated: animated)
-            Self.applyHeading(position.bearing, center: centerCoordinate, to: mapView, animated: animated)
+            Self.applyHeading(CameraBearing.toNativeHeading(position.bearing), center: centerCoordinate, to: mapView, animated: animated)
         }
 
         return true