diff --git a/core/src/main/java/info/openrocket/core/material/Material.java b/core/src/main/java/info/openrocket/core/material/Material.java
index 1b0e61f72..2fee1bd49 100644
--- a/core/src/main/java/info/openrocket/core/material/Material.java
+++ b/core/src/main/java/info/openrocket/core/material/Material.java
@@ -152,9 +152,9 @@ public abstract class Material implements Comparable<Material> {
 	private Material(String name, double density, MaterialGroup group, boolean userDefined, boolean documentMaterial) {
 		this.name = name;
 		this.density = density;
-		this.group = group;
 		this.userDefined = userDefined;
 		this.documentMaterial = documentMaterial;
+		this.group = getEquivalentGroup(group, userDefined);
 	}
 
 	private Material(String name, double density, MaterialGroup group, boolean userDefined) {
@@ -198,9 +198,13 @@ public abstract class Material implements Comparable<Material> {
 	/**
 	 * Some materials have a null group. This method returns the equivalent group, i.e. CUSTOM for user-defined materials,
 	 * and OTHER for materials with a null group.
+	 *
+	 * @param group: the group of the material
+	 * @param userDefined: whether the material is user-defined or not
+	 *
 	 * @return the equivalent group
 	 */
-	public MaterialGroup getEquivalentGroup() {
+	private static MaterialGroup getEquivalentGroup(MaterialGroup group, boolean userDefined) {
 		if (group != null) {
 			return group;
 		}
@@ -298,7 +302,7 @@ public abstract class Material implements Comparable<Material> {
 	}
 	
 	public String toStorableString() {
-		return getType().name() + "|" + name.replace('|', ' ') + '|' + density + '|' + getEquivalentGroup().getDatabaseString();
+		return getType().name() + "|" + name.replace('|', ' ') + '|' + density + '|' + group.getDatabaseString();
 	}
 	
 	
diff --git a/core/src/main/java/info/openrocket/core/preset/xml/BaseComponentDTO.java b/core/src/main/java/info/openrocket/core/preset/xml/BaseComponentDTO.java
index 03ef5e4c9..802df8e31 100644
--- a/core/src/main/java/info/openrocket/core/preset/xml/BaseComponentDTO.java
+++ b/core/src/main/java/info/openrocket/core/preset/xml/BaseComponentDTO.java
@@ -218,7 +218,7 @@ public abstract class BaseComponentDTO {
 		AnnotatedMaterialDTO(Material theMaterial) {
 			type = theMaterial.getType().name();
 			material = theMaterial.getName();
-			materialGroup = theMaterial.getEquivalentGroup().getDatabaseString();
+			materialGroup = theMaterial.getGroup().getDatabaseString();
 		}
 
 		public Material.Type getORMaterialType() {
diff --git a/core/src/main/java/info/openrocket/core/preset/xml/MaterialDTO.java b/core/src/main/java/info/openrocket/core/preset/xml/MaterialDTO.java
index 00f162d44..05db99714 100644
--- a/core/src/main/java/info/openrocket/core/preset/xml/MaterialDTO.java
+++ b/core/src/main/java/info/openrocket/core/preset/xml/MaterialDTO.java
@@ -40,7 +40,7 @@ public class MaterialDTO {
 	public MaterialDTO(final Material theMaterial) {
 		this(theMaterial.getName(), theMaterial.getDensity(), MaterialTypeDTO.asDTO(theMaterial.getType()),
 				theMaterial.getType().getUnitGroup().getDefaultUnit().toString(),
-				MaterialGroupDTO.asDTO(theMaterial.getEquivalentGroup()));
+				MaterialGroupDTO.asDTO(theMaterial.getGroup()));
 	}
 
 	public MaterialDTO(final String theName, final double theDensity, final MaterialTypeDTO theType,
diff --git a/swing/src/main/java/info/openrocket/swing/gui/configdialog/MaterialPanel.java b/swing/src/main/java/info/openrocket/swing/gui/configdialog/MaterialPanel.java
index a49e553e2..fcdd7e36c 100644
--- a/swing/src/main/java/info/openrocket/swing/gui/configdialog/MaterialPanel.java
+++ b/swing/src/main/java/info/openrocket/swing/gui/configdialog/MaterialPanel.java
@@ -210,7 +210,7 @@ public class MaterialPanel extends JPanel implements Invalidatable, Invalidating
             for (MaterialGroup group : sortedGroups) {
                 List<Material> itemsForGroup = new ArrayList<>();
                 for (Material material : materials) {
-                    materialGroup = material.getEquivalentGroup();
+                    materialGroup = material.getGroup();
                     if (materialGroup.equals(group)) {
                         itemsForGroup.add(material);
                     }
diff --git a/swing/src/main/java/info/openrocket/swing/gui/dialogs/CustomMaterialDialog.java b/swing/src/main/java/info/openrocket/swing/gui/dialogs/CustomMaterialDialog.java
index f868ae9e9..e9221877a 100644
--- a/swing/src/main/java/info/openrocket/swing/gui/dialogs/CustomMaterialDialog.java
+++ b/swing/src/main/java/info/openrocket/swing/gui/dialogs/CustomMaterialDialog.java
@@ -124,7 +124,7 @@ public class CustomMaterialDialog extends JDialog {
 		panel.add(new JLabel(trans.get("custmatdlg.lbl.MaterialGroup")));
 		groupBox = new JComboBox<>(MaterialGroup.ALL_GROUPS);
 		if (material != null && !material.isUserDefined()) {
-			groupBox.setSelectedItem(material.getEquivalentGroup());
+			groupBox.setSelectedItem(material.getGroup());
 		} else {
 			groupBox.setSelectedItem(MaterialGroup.CUSTOM);
 		}
diff --git a/swing/src/main/java/info/openrocket/swing/gui/dialogs/preferences/MaterialEditPanel.java b/swing/src/main/java/info/openrocket/swing/gui/dialogs/preferences/MaterialEditPanel.java
index 694ae6a0b..cba559903 100644
--- a/swing/src/main/java/info/openrocket/swing/gui/dialogs/preferences/MaterialEditPanel.java
+++ b/swing/src/main/java/info/openrocket/swing/gui/dialogs/preferences/MaterialEditPanel.java
@@ -105,7 +105,7 @@ public class MaterialEditPanel extends JPanel {
 				new Column(trans.get("matedtpan.col.Group")) {
 					@Override
 					public Object getValueAt(int row) {
-						return getMaterial(row).getEquivalentGroup().getName();
+						return getMaterial(row).getGroup().getName();
 					}
 
 					@Override