1 files changed, 4 insertions, 4 deletions

diff --git a/language/src/main/java/tools/refinery/language/validation/ProblemValidator.java b/language/src/main/java/tools/refinery/language/validation/ProblemValidator.java
index dfd386f5..3c10d39e 100644
--- a/language/src/main/java/tools/refinery/language/validation/ProblemValidator.java
+++ b/language/src/main/java/tools/refinery/language/validation/ProblemValidator.java
@@ -27,7 +27,7 @@ public class ProblemValidator extends AbstractProblemValidator {
 
         public static final String SINGLETON_VARIABLE_ISSUE = ISSUE_PREFIX + "SINGLETON_VARIABLE";
 
-        public static final String NON_UNIQUE_NODE_ISSUE = ISSUE_PREFIX + "NON_UNIQUE_NODE";
+        public static final String NON_INDIVIDUAL_NODE_ISSUE = ISSUE_PREFIX + "NON_INDIVIDUAL_NODE";
 
         @Inject
         private ReferenceCounter referenceCounter;
@@ -51,12 +51,12 @@ public class ProblemValidator extends AbstractProblemValidator {
         @Check
         public void checkNonUniqueNode(VariableOrNodeArgument argument) {
                 var variableOrNode = argument.getVariableOrNode();
-                if (variableOrNode instanceof Node node && !ProblemUtil.isUniqueNode(node)) {
+                if (variableOrNode instanceof Node node && !ProblemUtil.isIndividualNode(node)) {
                         var name = node.getName();
-                        var message = "Only unique nodes can be referenced in predicates. Mark '%s' as unique with the declaration 'unique %s.'"
+                        var message = "Only individual nodes can be referenced in predicates. Mark '%s' as individual with the declaration 'individual %s.'"
                                         .formatted(name, name);
                         error(message, argument, ProblemPackage.Literals.VARIABLE_OR_NODE_ARGUMENT__VARIABLE_OR_NODE,
-                                        INSIGNIFICANT_INDEX, NON_UNIQUE_NODE_ISSUE);
+                                        INSIGNIFICANT_INDEX, NON_INDIVIDUAL_NODE_ISSUE);
                 }
         }
 }