diff --git a/Celestia/src/main/cpp/CMakeLists.txt b/Celestia/src/main/cpp/CMakeLists.txt
index a6a15a9a..0d21e941 100644
--- a/Celestia/src/main/cpp/CMakeLists.txt
+++ b/Celestia/src/main/cpp/CMakeLists.txt
@@ -270,6 +270,8 @@ list(APPEND CELESTIA_SOURCES
         ${CELESTIA_SRC_DIR}/celengine/deepskyobj.h
         ${CELESTIA_SRC_DIR}/celengine/dsodb.cpp
         ${CELESTIA_SRC_DIR}/celengine/dsodb.h
+        ${CELESTIA_SRC_DIR}/celengine/dsodbbuilder.cpp
+        ${CELESTIA_SRC_DIR}/celengine/dsodbbuilder.h
         ${CELESTIA_SRC_DIR}/celengine/dsooctree.cpp
         ${CELESTIA_SRC_DIR}/celengine/dsooctree.h
         ${CELESTIA_SRC_DIR}/celengine/dsorenderer.cpp
@@ -315,6 +317,7 @@ list(APPEND CELESTIA_SOURCES
         ${CELESTIA_SRC_DIR}/celengine/name.h
         ${CELESTIA_SRC_DIR}/celengine/nebula.cpp
         ${CELESTIA_SRC_DIR}/celengine/nebula.h
+        ${CELESTIA_SRC_DIR}/celengine/octreebuilder.h
         ${CELESTIA_SRC_DIR}/celengine/objectrenderer.h
         ${CELESTIA_SRC_DIR}/celengine/observer.cpp
         ${CELESTIA_SRC_DIR}/celengine/observer.h
diff --git a/Celestia/src/main/cpp/CelestiaUniverse.cpp b/Celestia/src/main/cpp/CelestiaUniverse.cpp
index 82dbad19..8088a0c1 100644
--- a/Celestia/src/main/cpp/CelestiaUniverse.cpp
+++ b/Celestia/src/main/cpp/CelestiaUniverse.cpp
@@ -11,6 +11,7 @@
 
 #include "CelestiaSelection.h"
 #include <celengine/body.h>
+#include <celengine/observer.h>
 #include <celengine/starbrowser.h>
 #include <celengine/universe.h>
 #include <celutil/gettext.h>
diff --git a/app/src/main/java/space/celestia/mobilecelestia/MainActivity.kt b/app/src/main/java/space/celestia/mobilecelestia/MainActivity.kt
index 61409045..2a24180b 100644
--- a/app/src/main/java/space/celestia/mobilecelestia/MainActivity.kt
+++ b/app/src/main/java/space/celestia/mobilecelestia/MainActivity.kt
@@ -1968,8 +1968,9 @@ class MainActivity : AppCompatActivity(R.layout.activity_main),
     }
 
     companion object {
-        private const val CURRENT_DATA_VERSION = "80"
-        // 80: 1.7.2 Dev, Localization update data update (commit 5fdfe4e2fdda392920bd24d8d89d08f81b6f99df)
+        private const val CURRENT_DATA_VERSION = "81"
+        // 81: 1.7.4, Data update (commit 9f85700c021c0ef084c209a6e32b176bf95524d6)
+        // 80: 1.7.2, Localization update data update (commit 5fdfe4e2fdda392920bd24d8d89d08f81b6f99df)
         // 76: 1.7.1, Localization update data update (commit 4910ab33dad753673e1983a0493ef9230450391c)
         // 75: 1.7.0, Localization update data update (commit 6b9417781a6beb0ded8a1116c60c93c478830a2e)
         // 72: 1.6.8, Localization update, data update (commit 8241b5d3891df24e398ce329f7cf09a252370546)
diff --git a/jobs/build.yml b/jobs/build.yml
index f18be9c0..24ce0fd6 100644
--- a/jobs/build.yml
+++ b/jobs/build.yml
@@ -9,7 +9,7 @@ jobs:
     appCenterSecret: ${{ parameters.appCenterSecret }}
     appCenterToken: ${{ parameters.appCenterToken }}
     appCenterProject: ${{ parameters.appCenterProject }}
-    contentCommitHash: ${{ '5fdfe4e2fdda392920bd24d8d89d08f81b6f99df' }}
+    contentCommitHash: ${{ '9f85700c021c0ef084c209a6e32b176bf95524d6' }}
 
   steps:
   - checkout: Celestia