diff --git a/.sdkmanrc b/.sdkmanrc
deleted file mode 100644
index 9c3491ea..00000000
--- a/.sdkmanrc
+++ /dev/null
@@ -1,5 +0,0 @@
-# Used by JitPack's build (see jitpack.yml's `sdk env install`/`sdk env`) since
-# its build environment has SDKMAN pre-installed but not mise. Local dev uses
-# .mise.toml instead - keep both in sync.
-java=25.0.4-tem
-maven=3.9.16
diff --git a/pom.xml b/pom.xml
index 5bdd18ba..ed05ff29 100644
--- a/pom.xml
+++ b/pom.xml
@@ -130,7 +130,7 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-enforcer-plugin</artifactId>
-        <version>3.6.2</version>
+        <version>3.6.3</version>
         <executions>
           <execution>
             <id>enforce-maven</id>
@@ -140,8 +140,9 @@
             <configuration>
               <rules>
                 <requireMavenVersion>
-                  <!-- this is the version jitpack.io uses -->
-                  <version>3.6.2</version>
+                  <!-- JitPack uses this version to build. Highest confirmed working as of 2026-09-06;
+                       3.9.10+ failed. Verify with a build log before bumping. -->
+                  <version>3.9.9</version>
                 </requireMavenVersion>
               </rules>
             </configuration>
@@ -153,7 +154,7 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-compiler-plugin</artifactId>
-        <version>3.15.0</version>
+        <version>3.16.0</version>
         <configuration>
           <source>25</source>
           <target>25</target>
@@ -164,7 +165,7 @@
       <plugin>
         <groupId>org.codehaus.gmavenplus</groupId>
         <artifactId>gmavenplus-plugin</artifactId>
-        <version>4.3.1</version>
+        <version>5.1.0</version>
         <configuration>
           <targetBytecode>25</targetBytecode>
         </configuration>