diff --git a/.jitpack.yml b/.jitpack.yml
index 4f4d58a..b3fce73 100644
--- a/.jitpack.yml
+++ b/.jitpack.yml
@@ -1,4 +1,4 @@
 jdk:
-  - openjdk11
+  - openjdk17
 install:
   - ./gradlew build :library:publishToMavenLocal
diff --git a/build.gradle b/build.gradle
index c3b9582..4c1c4f9 100644
--- a/build.gradle
+++ b/build.gradle
@@ -7,7 +7,7 @@ buildscript {
         google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:7.1.3'
+        classpath 'com.android.tools.build:gradle:7.4.2'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
 
         // NOTE: Do not place your application dependencies here; they belong
diff --git a/library/build.gradle b/library/build.gradle
index 81b3cb7..36222a0 100644
--- a/library/build.gradle
+++ b/library/build.gradle
@@ -17,6 +17,15 @@ android {
             minifyEnabled false
         }
     }
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_17
+        targetCompatibility JavaVersion.VERSION_17
+    }
+
+    kotlinOptions {
+        jvmTarget = JavaVersion.VERSION_17.toString()
+    }
 }
 
 dependencies {
diff --git a/library/src/main/java/eu/kanade/tachiyomi/source/Source.kt b/library/src/main/java/eu/kanade/tachiyomi/source/Source.kt
index 4e00356..a61df58 100644
--- a/library/src/main/java/eu/kanade/tachiyomi/source/Source.kt
+++ b/library/src/main/java/eu/kanade/tachiyomi/source/Source.kt
@@ -22,24 +22,48 @@ interface Source {
     val name: String
 
     /**
-     * Returns an observable with the updated details for a manga.
+     * Get the updated details for a manga.
      *
+     * @since extensions-lib 1.4
      * @param manga the manga to update.
+     * @return the updated manga.
      */
-    fun fetchMangaDetails(manga: SManga): Observable<SManga>
+    suspend fun getMangaDetails(manga: SManga): SManga = throw Exception("Stub!")
 
     /**
-     * Returns an observable with all the available chapters for a manga.
+     * Get all the available chapters for a manga.
      *
+     * @since extensions-lib 1.4
      * @param manga the manga to update.
+     * @return the chapters for the manga.
      */
-    fun fetchChapterList(manga: SManga): Observable<List<SChapter>>
+    suspend fun getChapterList(manga: SManga): List<SChapter> = throw Exception("Stub!")
 
     /**
-     * Returns an observable with the list of pages a chapter has.
+     * Get the list of pages a chapter has. Pages should be returned
+     * in the expected order; the index is ignored.
      *
+     * @since extensions-lib 1.4
      * @param chapter the chapter.
+     * @return the pages for the chapter.
      */
-    fun fetchPageList(chapter: SChapter): Observable<List<Page>>
+    suspend fun getPageList(chapter: SChapter): List<Page> = throw Exception("Stub!")
 
+    @Deprecated(
+        "Use the non-RxJava API instead",
+        ReplaceWith("getMangaDetails"),
+    )
+    fun fetchMangaDetails(manga: SManga): Observable<SManga> = throw Exception("Stub!")
+
+    @Deprecated(
+        "Use the non-RxJava API instead",
+        ReplaceWith("getChapterList"),
+    )
+    fun fetchChapterList(manga: SManga): Observable<List<SChapter>> = throw Exception("Stub!")
+
+    @Deprecated(
+        "Use the non-RxJava API instead",
+        ReplaceWith("getPageList"),
+    )
+    fun fetchPageList(chapter: SChapter): Observable<List<Page>> = throw Exception("Stub!")
 }
\ No newline at end of file
diff --git a/settings.gradle b/settings.gradle
deleted file mode 100644
index d8f14a1..0000000
--- a/settings.gradle
+++ /dev/null
@@ -1 +0,0 @@
-include ':library'
diff --git a/settings.gradle.kts b/settings.gradle.kts
new file mode 100644
index 0000000..be2dccf
--- /dev/null
+++ b/settings.gradle.kts
@@ -0,0 +1 @@
+include(":library")