diff --git a/.github/workflows/_static-analysis.yml b/.github/workflows/_static-analysis.yml
index cc96ec2e8..491599990 100644
--- a/.github/workflows/_static-analysis.yml
+++ b/.github/workflows/_static-analysis.yml
@@ -20,4 +20,4 @@ jobs:
           cache: "maven"
 
       - name: Check Code Style
-        run: mvn --update-snapshots --no-transfer-progress spotless:check
+        run: mvn --update-snapshots --no-transfer-progress spotless:check pmd:check
diff --git a/pom.xml b/pom.xml
index 7f77f70f9..68a538883 100644
--- a/pom.xml
+++ b/pom.xml
@@ -94,6 +94,17 @@
             <target>1.8</target>
           </configuration>
         </plugin>
+          <plugin>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-pmd-plugin</artifactId>
+            <version>3.23.0</version>
+            <configuration>
+              <linkXRef>false</linkXRef>
+              <printFailingErrors>true</printFailingErrors>
+              <failurePriority>3</failurePriority>
+              <targetJdk>1.8</targetJdk>
+            </configuration>
+          </plugin>
         <plugin>
           <groupId>com.diffplug.spotless</groupId>
           <artifactId>spotless-maven-plugin</artifactId>
diff --git a/src/main/java/com/mindee/geometry/Point.java b/src/main/java/com/mindee/geometry/Point.java
index cbcc2bbe4..fb925d790 100644
--- a/src/main/java/com/mindee/geometry/Point.java
+++ b/src/main/java/com/mindee/geometry/Point.java
@@ -30,4 +30,9 @@ public boolean equals(Object object) {
     Point point = (Point) object;
     return this.x.equals(point.x) && this.y.equals(point.y);
   }
+
+  @Override
+  public int hashCode() {
+    return x.hashCode() + y.hashCode();
+  }
 }
diff --git a/src/main/java/com/mindee/geometry/Polygon.java b/src/main/java/com/mindee/geometry/Polygon.java
index d76a317ef..8369204b0 100644
--- a/src/main/java/com/mindee/geometry/Polygon.java
+++ b/src/main/java/com/mindee/geometry/Polygon.java
@@ -83,4 +83,9 @@ public boolean equals(Object object) {
     }
     return true;
   }
+
+  @Override
+  public int hashCode() {
+    return coordinates.hashCode();
+  }
 }
diff --git a/src/main/java/com/mindee/http/MindeeHttpApiV2.java b/src/main/java/com/mindee/http/MindeeHttpApiV2.java
index ad1c1e67e..c8a4f832d 100644
--- a/src/main/java/com/mindee/http/MindeeHttpApiV2.java
+++ b/src/main/java/com/mindee/http/MindeeHttpApiV2.java
@@ -73,7 +73,7 @@ public JobResponse reqPostInferenceEnqueue(
       InferenceParameters options
   ) {
     String url = this.mindeeSettings.getBaseUrl() + "/inferences/enqueue";
-    HttpPost post = buildHttpPost(url, options);
+    HttpPost post = buildHttpPost(url);
 
     MultipartEntityBuilder builder = MultipartEntityBuilder.create();
     builder.setMode(HttpMultipartMode.EXTENDED);
@@ -101,7 +101,7 @@ public JobResponse reqPostInferenceEnqueue(
       InferenceParameters options
   ) {
     String url = this.mindeeSettings.getBaseUrl() + "/inferences/enqueue";
-    HttpPost post = buildHttpPost(url, options);
+    HttpPost post = buildHttpPost(url);
 
     MultipartEntityBuilder builder = MultipartEntityBuilder.create();
     builder.setMode(HttpMultipartMode.EXTENDED);
@@ -112,7 +112,7 @@ public JobResponse reqPostInferenceEnqueue(
 
   /**
    * Executes an enqueue action, common to URL & local inputs.
-   * 
+   *
    * @param post HTTP Post object.
    * @return a valid job response.
    */
@@ -253,7 +253,7 @@ private HttpEntity buildHttpBody(MultipartEntityBuilder builder, InferenceParame
     return builder.build();
   }
 
-  private HttpPost buildHttpPost(String url, InferenceParameters params) {
+  private HttpPost buildHttpPost(String url) {
     HttpPost post;
     try {
       URIBuilder uriBuilder = new URIBuilder(url);
diff --git a/src/main/java/com/mindee/input/InputSourceUtils.java b/src/main/java/com/mindee/input/InputSourceUtils.java
index 9ebbc15a9..1c1b1eff4 100644
--- a/src/main/java/com/mindee/input/InputSourceUtils.java
+++ b/src/main/java/com/mindee/input/InputSourceUtils.java
@@ -71,14 +71,12 @@ public static String[] splitNameStrict(String filename) throws MindeeException {
    * Returns true if the file is a PDF.
    */
   public static boolean isPdf(byte[] fileBytes) {
-    try (
-        PDDocument document = Loader
-          .loadPDF(new RandomAccessReadBuffer(new ByteArrayInputStream(fileBytes)))
-    ) {
-      return true;
+    try {
+      Loader.loadPDF(new RandomAccessReadBuffer(new ByteArrayInputStream(fileBytes)));
     } catch (IOException e) {
       return false;
     }
+    return true;
   }
 
   /**