diff --git a/core/src/net/sf/openrocket/file/wavefrontobj/export/OBJExporterFactory.java b/core/src/net/sf/openrocket/file/wavefrontobj/export/OBJExporterFactory.java
index b9e6f52b3..11a607146 100644
--- a/core/src/net/sf/openrocket/file/wavefrontobj/export/OBJExporterFactory.java
+++ b/core/src/net/sf/openrocket/file/wavefrontobj/export/OBJExporterFactory.java
@@ -154,6 +154,7 @@ public class OBJExporterFactory {
 
             // Component exporting
             String groupName = idx + "_" + component.getName();
+            groupName = sanitizeGroupName(groupName);
             handleComponent(obj, this.configuration, this.options.getTransformer(), component, groupName,
                     materials.get(obj), this.options.getLOD(), options, warnings);
 
@@ -293,6 +294,20 @@ public class OBJExporterFactory {
         return sortedComponents;
     }
 
+    /**
+     * Sanitize the group name by replacing illegal characters with underscores.
+     * @param groupName the group name to sanitize
+     * @return the sanitized group name
+     */
+    private static String sanitizeGroupName(String groupName) {
+        Character c = FileUtils.getIllegalFilenameChar(groupName);
+        while (c != null) {
+            groupName = groupName.replace(c, '_');
+            c = FileUtils.getIllegalFilenameChar(groupName);
+        }
+        return groupName;
+    }
+
     private void addChildComponentToList(RocketComponent parent, Set<RocketComponent> components, Set<RocketComponent> sortedComponents) {
         for (RocketComponent child : parent.getChildren()) {
             if (components.contains(child)) {