diff --git a/Projects/MapViewer/Android/DxLib_Default/app/build.gradle.kts b/Projects/MapViewer/Android/DxLib_Default/app/build.gradle.kts
index f44014ff5..eaf5d7efd 100644
--- a/Projects/MapViewer/Android/DxLib_Default/app/build.gradle.kts
+++ b/Projects/MapViewer/Android/DxLib_Default/app/build.gradle.kts
@@ -16,7 +16,7 @@ android {
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
         externalNativeBuild {
             cmake {
-                cppFlags += "-std=c++17"
+                cppFlags += "-std=c++2b"
             }
         }
     }
diff --git a/Projects/MapViewer/Android/DxLib_Mahoroba/app/build.gradle.kts b/Projects/MapViewer/Android/DxLib_Mahoroba/app/build.gradle.kts
index 017cfd25d..c912623a3 100644
--- a/Projects/MapViewer/Android/DxLib_Mahoroba/app/build.gradle.kts
+++ b/Projects/MapViewer/Android/DxLib_Mahoroba/app/build.gradle.kts
@@ -16,7 +16,7 @@ android {
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
         externalNativeBuild {
             cmake {
-                cppFlags += "-std=c++17"
+                cppFlags += "-std=c++2b"
             }
         }
     }