diff --git a/model/src/main/java/org/onehippo/cm/model/parser/ConfigSourceParser.java b/model/src/main/java/org/onehippo/cm/model/parser/ConfigSourceParser.java
index b2f41db..987d1c1 100644
--- a/model/src/main/java/org/onehippo/cm/model/parser/ConfigSourceParser.java
+++ b/model/src/main/java/org/onehippo/cm/model/parser/ConfigSourceParser.java
@@ -16,6 +16,7 @@
 package org.onehippo.cm.model.parser;
 
 import java.net.URI;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 
@@ -44,6 +45,7 @@ import static org.onehippo.cm.model.Constants.META_IGNORE_REORDERED_CHILDREN;
 import static org.onehippo.cm.model.Constants.META_ORDER_BEFORE_KEY;
 import static org.onehippo.cm.model.Constants.META_RESIDUAL_CHILD_NODE_CATEGORY_KEY;
 import static org.onehippo.cm.model.Constants.URI_KEY;
+import static org.yaml.snakeyaml.nodes.NodeId.scalar;
 
 public class ConfigSourceParser extends SourceParser {
 
@@ -175,7 +177,13 @@ public class ConfigSourceParser extends SourceParser {
     }
 
     private void constructWebFileBundleDefinition(final Node definitionNode, final ConfigSourceImpl source) throws ParserException {
-        final List<Node> nodes = asSequence(definitionNode);
+        List<Node> nodes;
+        if (definitionNode.getNodeId() == scalar) {
+            nodes = new ArrayList<>();
+            nodes.add(asScalar(definitionNode));
+        } else {
+            nodes = asSequence(definitionNode);
+        }
         for (Node node : nodes) {
             final String name = asStringScalar(node);
             for (Definition definition : source.getModifiableDefinitions()) {
diff --git a/model/src/main/java/org/onehippo/cm/model/serializer/SourceSerializer.java b/model/src/main/java/org/onehippo/cm/model/serializer/SourceSerializer.java
index 648506e..1773ba7 100644
--- a/model/src/main/java/org/onehippo/cm/model/serializer/SourceSerializer.java
+++ b/model/src/main/java/org/onehippo/cm/model/serializer/SourceSerializer.java
@@ -112,7 +112,10 @@ public class SourceSerializer extends AbstractBaseSerializer {
         if (contentDefinitionTuples.size() > 0) {
             definitionNodes.add(createStrOptionalSequenceTuple(DefinitionType.CONTENT.toString(), contentDefinitionTuples));
         }
-        if (webFilesDefinitionNodes.size() > 0) {
+        if (webFilesDefinitionNodes.size() == 1) {
+            definitionNodes.add(new NodeTuple(createStrScalar(DefinitionType.WEBFILEBUNDLE.toString()), webFilesDefinitionNodes.get(0)));
+        }
+        else if (webFilesDefinitionNodes.size() > 1) {
             definitionNodes.add(createStrSeqTuple(DefinitionType.WEBFILEBUNDLE.toString(), webFilesDefinitionNodes, true));
         }
 
diff --git a/model/src/test/java/org/onehippo/cm/model/parser/SourceValidationTest.java b/model/src/test/java/org/onehippo/cm/model/parser/SourceValidationTest.java
index 2961f16..30c117d 100644
--- a/model/src/test/java/org/onehippo/cm/model/parser/SourceValidationTest.java
+++ b/model/src/test/java/org/onehippo/cm/model/parser/SourceValidationTest.java
@@ -1038,19 +1038,19 @@ public class SourceValidationTest extends AbstractBaseTest {
     }
 
     @Test
-    public void webFileBundleWithScalarValue() {
+    public void webFileBundleWithNonStringScalarValue() {
         final String yaml = "definitions:\n"
                 + "  webfilebundle:\n"
-                + "    scalar";
+                + "    42";
 
         final Node root = yamlParser.compose(new StringReader(yaml));
         final Node webFilesValue = firstDefinitionTuple(root).getValueNode();
 
-        assertParserException(root, webFilesValue, "Node must be a sequence");
+        assertParserException(root, webFilesValue, "Scalar must be a string");
     }
 
     @Test
-    public void webFileBundleWithNonStringValue() {
+    public void webFileBundleWithNonStringSequenceValue() {
         final String yaml = "definitions:\n"
                 + "  webfilebundle: [42]";
 
diff --git a/model/src/test/resources/parser/hierarchy_test/hcm-config/base/project1/module1/config.yaml b/model/src/test/resources/parser/hierarchy_test/hcm-config/base/project1/module1/config.yaml
index 4c0fae8..43235ed 100644
--- a/model/src/test/resources/parser/hierarchy_test/hcm-config/base/project1/module1/config.yaml
+++ b/model/src/test/resources/parser/hierarchy_test/hcm-config/base/project1/module1/config.yaml
@@ -56,4 +56,4 @@ definitions:
           operation: add
           type: name
           value: ['some:mixin']
-  webfilebundle: [site]
+  webfilebundle: site