diff --git a/.github/workflows/maven.yml b/.github/workflows/maven.yml
index 15744c3..759e97c 100644
--- a/.github/workflows/maven.yml
+++ b/.github/workflows/maven.yml
@@ -99,6 +99,16 @@ jobs:
           set -o pipefail
           mvn -B -Dmeos.lib.dir=/usr/local/lib clean test | tee "$RUNNER_TEMP/build.log"
 
+      # The build prints no warning: Maven's [WARNING] lines and the WARNING:
+      # lines JUnit and the JVM print during the tests. One of either fails
+      # the step and is listed.
+      - name: Refuse a build warning
+        run: |
+          if grep -E '^\[WARNING\]|^WARNING:' "$RUNNER_TEMP/build.log"; then
+            echo "::error::the build prints $(grep -cE '^\[WARNING\]|^WARNING:' "$RUNNER_TEMP/build.log") warning line(s)"
+            exit 1
+          fi
+
       # The build's own summary states two things this job's conclusion does
       # not: a test reported SKIPPED asserts nothing while the job still reads
       # success, and a test the run never collects appears in no count at all,
diff --git a/benchmark/pom.xml b/benchmark/pom.xml
index 6124fd1..bf4a42d 100644
--- a/benchmark/pom.xml
+++ b/benchmark/pom.xml
@@ -93,12 +93,6 @@
         </dependency>
 
         <!-- JUnit dependency -->
-        <dependency>
-            <groupId>org.junit.jupiter</groupId>
-            <artifactId>junit-jupiter-api</artifactId>
-            <version>5.7.0</version>
-            <scope>test</scope>
-        </dependency>
 
         <!-- Jackson dependencies for JSON processing -->
         <dependency>
diff --git a/benchmark/src/main/java/org/mobilitydb/meos/MeosSetSetJoin.java b/benchmark/src/main/java/org/mobilitydb/meos/MeosSetSetJoin.java
index 759b07f..08ea2cb 100644
--- a/benchmark/src/main/java/org/mobilitydb/meos/MeosSetSetJoin.java
+++ b/benchmark/src/main/java/org/mobilitydb/meos/MeosSetSetJoin.java
@@ -1,12 +1,11 @@
 package org.mobilitydb.meos;
 
+import com.kenai.jffi.MemoryIO;
 import functions.GeneratedFunctions;
 import java.lang.ref.Reference;
-import java.lang.reflect.Field;
 import jnr.ffi.Memory;
 import jnr.ffi.Pointer;
 import jnr.ffi.Runtime;
-import sun.misc.Unsafe;
 
 /**
  * NxN cross-stream set-set join operator over two arrays of temporal geometries.
@@ -23,10 +22,11 @@
  *
  * <p>The backing C functions take {@code (Temporal **arr1, int n1, Temporal **arr2, int n2,
  * [double dist,] int *count [, SpanSet ***periods])} and return a flat {@code int *} of
- * {@code 2*count} indices (caller frees). Native result buffers are freed via {@code Unsafe}.
+ * {@code 2*count} indices (caller frees). Native result buffers are freed through jffi's {@code MemoryIO}, which calls the system
+ * free MEOS allocates with.
  */
 public final class MeosSetSetJoin {
-    private static final Unsafe UNSAFE;
+    private static final MemoryIO IO = MemoryIO.getInstance();
 
     private MeosSetSetJoin() {
     }
@@ -113,17 +113,7 @@ private static int[][] readPairsAndFree(Pointer res, int cnt) {
 
     private static void free(Pointer p) {
         if (p != null) {
-            UNSAFE.freeMemory(p.address());
-        }
-    }
-
-    static {
-        try {
-            Field f = Unsafe.class.getDeclaredField("theUnsafe");
-            f.setAccessible(true);
-            UNSAFE = (Unsafe) f.get(null);
-        } catch (ReflectiveOperationException e) {
-            throw new ExceptionInInitializerError(e);
+            IO.freeMemory(p.address());
         }
     }
 
diff --git a/binding/src/main/java/org/mobilitydb/meos/MeosSetSetJoin.java b/binding/src/main/java/org/mobilitydb/meos/MeosSetSetJoin.java
index 759b07f..08ea2cb 100644
--- a/binding/src/main/java/org/mobilitydb/meos/MeosSetSetJoin.java
+++ b/binding/src/main/java/org/mobilitydb/meos/MeosSetSetJoin.java
@@ -1,12 +1,11 @@
 package org.mobilitydb.meos;
 
+import com.kenai.jffi.MemoryIO;
 import functions.GeneratedFunctions;
 import java.lang.ref.Reference;
-import java.lang.reflect.Field;
 import jnr.ffi.Memory;
 import jnr.ffi.Pointer;
 import jnr.ffi.Runtime;
-import sun.misc.Unsafe;
 
 /**
  * NxN cross-stream set-set join operator over two arrays of temporal geometries.
@@ -23,10 +22,11 @@
  *
  * <p>The backing C functions take {@code (Temporal **arr1, int n1, Temporal **arr2, int n2,
  * [double dist,] int *count [, SpanSet ***periods])} and return a flat {@code int *} of
- * {@code 2*count} indices (caller frees). Native result buffers are freed via {@code Unsafe}.
+ * {@code 2*count} indices (caller frees). Native result buffers are freed through jffi's {@code MemoryIO}, which calls the system
+ * free MEOS allocates with.
  */
 public final class MeosSetSetJoin {
-    private static final Unsafe UNSAFE;
+    private static final MemoryIO IO = MemoryIO.getInstance();
 
     private MeosSetSetJoin() {
     }
@@ -113,17 +113,7 @@ private static int[][] readPairsAndFree(Pointer res, int cnt) {
 
     private static void free(Pointer p) {
         if (p != null) {
-            UNSAFE.freeMemory(p.address());
-        }
-    }
-
-    static {
-        try {
-            Field f = Unsafe.class.getDeclaredField("theUnsafe");
-            f.setAccessible(true);
-            UNSAFE = (Unsafe) f.get(null);
-        } catch (ReflectiveOperationException e) {
-            throw new ExceptionInInitializerError(e);
+            IO.freeMemory(p.address());
         }
     }