diff --git a/applications/src/main/java/boofcv/app/BaseFiducialSquare.java b/applications/src/main/java/boofcv/app/BaseFiducialSquare.java
index 350a17eff8..1c027e684d 100644
--- a/applications/src/main/java/boofcv/app/BaseFiducialSquare.java
+++ b/applications/src/main/java/boofcv/app/BaseFiducialSquare.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, Peter Abeles. All Rights Reserved.
+ * Copyright (c) 2024, Peter Abeles. All Rights Reserved.
  *
  * This file is part of BoofCV (http://boofcv.org).
  *
@@ -28,6 +28,7 @@
 import org.kohsuke.args4j.Option;
 
 import java.io.IOException;
+import java.util.Locale;
 
 /**
  * <p>
@@ -163,7 +164,7 @@ private void getFileTypeFromFileName() {
 			fileType = "pdf";
 			fileName += ".pdf";
 		}
-		fileType = fileType.toLowerCase();
+		fileType = fileType.toLowerCase(Locale.ENGLISH);
 	}
 
 	private static void failExit( String message ) {
diff --git a/applications/src/main/java/boofcv/app/CreateAztecCodeDocument.java b/applications/src/main/java/boofcv/app/CreateAztecCodeDocument.java
index b4a1de6953..e8b301c7ed 100644
--- a/applications/src/main/java/boofcv/app/CreateAztecCodeDocument.java
+++ b/applications/src/main/java/boofcv/app/CreateAztecCodeDocument.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, Peter Abeles. All Rights Reserved.
+ * Copyright (c) 2024, Peter Abeles. All Rights Reserved.
  *
  * This file is part of BoofCV (http://boofcv.org).
  *
@@ -35,6 +35,7 @@
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Locale;
 import java.util.Objects;
 
 /**
@@ -210,7 +211,7 @@ private void getFileTypeFromFileName() {
 			fileType = "pdf";
 			fileName += ".pdf";
 		}
-		fileType = fileType.toLowerCase();
+		fileType = fileType.toLowerCase(Locale.ENGLISH);
 	}
 
 	public static void main( String[] args ) {
diff --git a/applications/src/main/java/boofcv/app/CreateMicroQrDocument.java b/applications/src/main/java/boofcv/app/CreateMicroQrDocument.java
index 0b515b4026..a1e54973c7 100644
--- a/applications/src/main/java/boofcv/app/CreateMicroQrDocument.java
+++ b/applications/src/main/java/boofcv/app/CreateMicroQrDocument.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, Peter Abeles. All Rights Reserved.
+ * Copyright (c) 2024, Peter Abeles. All Rights Reserved.
  *
  * This file is part of BoofCV (http://boofcv.org).
  *
@@ -37,6 +37,7 @@
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Locale;
 import java.util.Objects;
 
 /**
@@ -225,7 +226,7 @@ private void getFileTypeFromFileName() {
 			fileType = "pdf";
 			fileName += ".pdf";
 		}
-		fileType = fileType.toLowerCase();
+		fileType = fileType.toLowerCase(Locale.ENGLISH);
 	}
 
 	public static void main( String[] args ) {
diff --git a/applications/src/main/java/boofcv/app/CreateQrCodeDocument.java b/applications/src/main/java/boofcv/app/CreateQrCodeDocument.java
index aa4deeb644..11ba863dca 100644
--- a/applications/src/main/java/boofcv/app/CreateQrCodeDocument.java
+++ b/applications/src/main/java/boofcv/app/CreateQrCodeDocument.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, Peter Abeles. All Rights Reserved.
+ * Copyright (c) 2024, Peter Abeles. All Rights Reserved.
  *
  * This file is part of BoofCV (http://boofcv.org).
  *
@@ -36,6 +36,7 @@
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Locale;
 import java.util.Objects;
 
 /**
@@ -201,7 +202,7 @@ private void getFileTypeFromFileName() {
 			fileType = "pdf";
 			fileName += ".pdf";
 		}
-		fileType = fileType.toLowerCase();
+		fileType = fileType.toLowerCase(Locale.ENGLISH);
 	}
 
 	public static void main( String[] args ) {
diff --git a/applications/src/main/java/boofcv/app/MeshViewerApp.java b/applications/src/main/java/boofcv/app/MeshViewerApp.java
index b9e259dd97..c8d250e23e 100644
--- a/applications/src/main/java/boofcv/app/MeshViewerApp.java
+++ b/applications/src/main/java/boofcv/app/MeshViewerApp.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023, Peter Abeles. All Rights Reserved.
+ * Copyright (c) 2024, Peter Abeles. All Rights Reserved.
  *
  * This file is part of BoofCV (http://boofcv.org).
  *
@@ -31,6 +31,7 @@
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
+import java.util.Locale;
 
 /**
  * Very simple app for opening and viewing a 3D mesh
@@ -46,7 +47,7 @@ private static void loadFile( File file ) {
 		// Load the mesh
 		var mesh = new VertexMesh();
 		var colors = new DogArray_I32();
-		String extension = FilenameUtils.getExtension(file.getName()).toLowerCase();
+		String extension = FilenameUtils.getExtension(file.getName()).toLowerCase(Locale.ENGLISH);
 		var type = switch (extension) {
 			case "ply" -> PointCloudIO.Format.PLY;
 			case "stl" -> PointCloudIO.Format.STL;
diff --git a/applications/src/main/java/boofcv/app/fiducials/CreateFiducialDocumentPDF.java b/applications/src/main/java/boofcv/app/fiducials/CreateFiducialDocumentPDF.java
index 18ab4f842c..ecf0f540f6 100644
--- a/applications/src/main/java/boofcv/app/fiducials/CreateFiducialDocumentPDF.java
+++ b/applications/src/main/java/boofcv/app/fiducials/CreateFiducialDocumentPDF.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, Peter Abeles. All Rights Reserved.
+ * Copyright (c) 2024, Peter Abeles. All Rights Reserved.
  *
  * This file is part of BoofCV (http://boofcv.org).
  *
@@ -39,6 +39,7 @@
 import java.io.OutputStream;
 import java.io.PrintStream;
 import java.util.List;
+import java.util.Locale;
 
 /**
  * Generates the fiducial PDF Document
@@ -272,7 +273,7 @@ public void sendToPrinter() {
 
 	public void saveToDisk( String documentName ) throws IOException {
 		// ensure that it has the correct suffix
-		if (!documentName.toLowerCase().endsWith(".pdf")) {
+		if (!documentName.toLowerCase(Locale.ENGLISH).endsWith(".pdf")) {
 			documentName += ".pdf";
 		}