diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc
index c9506e47f..1b3ad10d8 100644
--- a/CHANGELOG.adoc
+++ b/CHANGELOG.adoc
@@ -31,6 +31,7 @@ It has long been unused by Sirius Web itself (since the transition to MUI).
 - https://github.com/eclipse-syson/syson/issues/2237[#2237] [diagrams] Fix the item label inside `frames`, `require constraints`, and `assume constraints` compartments.
 - https://github.com/eclipse-syson/syson/issues/2278[#2278] [diagrams] Display inherited behavior parameters in the _parameters_ compartment of `ActionDefinition` and `ActionUsage` graphical nodes.
 - https://github.com/eclipse-syson/syson/issues/2291[#2291] [diagrams] Fix item label for constraint to show their name and expression value between braces (if present).
+- https://github.com/eclipse-syson/syson/issues/2289[#2289] [details] Fix expression support for `TransitionUsage`.
 
 === Improvements
 
diff --git a/backend/application/syson-application-configuration/src/main/java/org/eclipse/syson/application/configuration/SysMLv2PropertiesConfigurer.java b/backend/application/syson-application-configuration/src/main/java/org/eclipse/syson/application/configuration/SysMLv2PropertiesConfigurer.java
index 9c51c98d1..71c630df0 100644
--- a/backend/application/syson-application-configuration/src/main/java/org/eclipse/syson/application/configuration/SysMLv2PropertiesConfigurer.java
+++ b/backend/application/syson-application-configuration/src/main/java/org/eclipse/syson/application/configuration/SysMLv2PropertiesConfigurer.java
@@ -193,6 +193,7 @@ private FormDescription createDetailsViewForElement() {
         pageCore.getGroups().add(this.createFeatureValuePropertiesGroup());
         pageCore.getGroups().add(this.createExpressionPropertiesGroup());
         pageCore.getGroups().add(this.createResultExpressionPropertiesGroup());
+        pageCore.getGroups().add(this.createGuardExpressionPropertiesGroup());
 
         PageDescription pageAdvanced = FormFactory.eINSTANCE.createPageDescription();
         pageAdvanced.setName("SysON-DetailsView-Advanced");
@@ -208,49 +209,23 @@ private FormDescription createDetailsViewForElement() {
     }
 
     /**
-     * Creates a group to display the value of an Expression.
+     * Creates a group to display the value of an actual Expression (selected directly).
      *
      * @return a {@link GroupDescription}
      */
     private GroupDescription createExpressionPropertiesGroup() {
-        GroupDescription group = FormFactory.eINSTANCE.createGroupDescription();
-        group.setDisplayMode(GroupDisplayMode.LIST);
-        group.setName("Expression Value");
-        group.setLabelExpression("");
-        group.setSemanticCandidatesExpression(ServiceMethod.of0(DetailsViewService::getExpression).aqlSelf());
-
-        TextAreaDescription expressionWidget = FormFactory.eINSTANCE.createTextAreaDescription();
-        expressionWidget.setName("Expression");
-        expressionWidget.setLabelExpression(CUSTOM_EXPRESSION_WIDGET_KEY);
-        expressionWidget.setValueExpression(ServiceMethod.of0(DetailsViewService::getExpressionTextualRepresentation).aqlSelf());
-        expressionWidget.setIsEnabledExpression(AQLConstants.AQL_FALSE);
-
-        group.getChildren().add(expressionWidget);
-
-        return group;
+        return this.createExpressionPropertiesGroup(ServiceMethod.of0(DetailsViewService::getExpression).aqlSelf(),
+                ServiceMethod.of0(DetailsViewService::getExpressionTextualRepresentation).aqlSelf());
     }
 
     /**
-     * Creates a group to display the value of a Feature or FeatureValue.
+     * Creates a group to display the Expression defining the value of a Feature or FeatureValue.
      *
      * @return a {@link GroupDescription}
      */
     private GroupDescription createFeatureValuePropertiesGroup() {
-        GroupDescription group = FormFactory.eINSTANCE.createGroupDescription();
-        group.setDisplayMode(GroupDisplayMode.LIST);
-        group.setName("Value");
-        group.setLabelExpression("");
-        group.setSemanticCandidatesExpression(ServiceMethod.of0(DetailsViewService::getFeatureValue).aqlSelf());
-
-        TextAreaDescription expressionWidget = FormFactory.eINSTANCE.createTextAreaDescription();
-        expressionWidget.setName("ValueExpression");
-        expressionWidget.setLabelExpression(CUSTOM_EXPRESSION_WIDGET_KEY);
-        expressionWidget.setValueExpression(ServiceMethod.of0(DetailsViewService::getValueExpressionTextualRepresentation).aqlSelf());
-        expressionWidget.setIsEnabledExpression(AQLConstants.AQL_FALSE);
-
-        group.getChildren().add(expressionWidget);
-
-        return group;
+        return this.createExpressionPropertiesGroup(ServiceMethod.of0(DetailsViewService::getFeatureValue).aqlSelf(),
+                ServiceMethod.of0(DetailsViewService::getValueExpressionTextualRepresentation).aqlSelf());
     }
 
     /**
@@ -259,17 +234,40 @@ private GroupDescription createFeatureValuePropertiesGroup() {
      * @return a {@link GroupDescription}
      */
     private GroupDescription createResultExpressionPropertiesGroup() {
+        return this.createExpressionPropertiesGroup(ServiceMethod.of0(DetailsViewService::getResultExpression).aqlSelf(),
+                ServiceMethod.of0(DetailsViewService::getResultExpressionTextualRepresentation).aqlSelf());
+    }
+
+    /**
+     * Creates a group to display the value of a guard expression.
+     *
+     * @return a {@link GroupDescription}
+     */
+    private GroupDescription createGuardExpressionPropertiesGroup() {
+        return this.createExpressionPropertiesGroup(ServiceMethod.of0(DetailsViewService::getGuardExpression).aqlSelf(),
+                ServiceMethod.of0(DetailsViewService::getExpressionTextualRepresentation).aqlSelf());
+    }
+
+    /**
+     * Helper to create a group to display an existing expression.
+     *
+     * @param semanticCandidatesExpression
+     *            the AQL expression to find the semantic candidate.
+     * @param valueExpression
+     *            the AQL expression to render the text of the expression corresponding to the semantic candidate.
+     * @return a {@link GroupDescription}
+     */
+    private GroupDescription createExpressionPropertiesGroup(String semanticCandidatesExpression, String valueExpression) {
         GroupDescription group = FormFactory.eINSTANCE.createGroupDescription();
         group.setDisplayMode(GroupDisplayMode.LIST);
-        group.setName("Result");
+        group.setName("Expression Value");
         group.setLabelExpression("");
-        group.setSemanticCandidatesExpression(ServiceMethod.of0(DetailsViewService::getResultExpression).aqlSelf());
+        group.setSemanticCandidatesExpression(semanticCandidatesExpression);
 
-        TextAreaDescription expressionWidget = FormFactory.eINSTANCE.createTextAreaDescription();
-        expressionWidget.setName("ResultExpression");
+        LabelDescription expressionWidget = FormFactory.eINSTANCE.createLabelDescription();
+        expressionWidget.setName("Expression");
         expressionWidget.setLabelExpression(CUSTOM_EXPRESSION_WIDGET_KEY);
-        expressionWidget.setValueExpression(ServiceMethod.of0(DetailsViewService::getResultExpressionTextualRepresentation).aqlSelf());
-        expressionWidget.setIsEnabledExpression(AQLConstants.AQL_FALSE);
+        expressionWidget.setValueExpression(valueExpression);
 
         group.getChildren().add(expressionWidget);
 
diff --git a/backend/application/syson-application-configuration/src/main/java/org/eclipse/syson/application/services/DetailsViewService.java b/backend/application/syson-application-configuration/src/main/java/org/eclipse/syson/application/services/DetailsViewService.java
index a7c338ce1..4b418cb84 100644
--- a/backend/application/syson-application-configuration/src/main/java/org/eclipse/syson/application/services/DetailsViewService.java
+++ b/backend/application/syson-application-configuration/src/main/java/org/eclipse/syson/application/services/DetailsViewService.java
@@ -68,6 +68,7 @@
 import org.eclipse.syson.sysml.Succession;
 import org.eclipse.syson.sysml.SysmlFactory;
 import org.eclipse.syson.sysml.SysmlPackage;
+import org.eclipse.syson.sysml.TransitionFeatureMembership;
 import org.eclipse.syson.sysml.TransitionUsage;
 import org.eclipse.syson.sysml.Type;
 import org.eclipse.syson.sysml.Usage;
@@ -651,6 +652,23 @@ public Element getResultExpression(Element self) {
         return result;
     }
 
+    /**
+     * Gets the guard expression from a {@ink TransitionUsage} or {@link TransitionFeatureMembership}.
+     *
+     * @param self
+     *            {@ink TransitionUsage} or {@link TransitionFeatureMembership}.
+     * @return the corresponding guard {@link Expression} or <code>null</code>
+     */
+    public Expression getGuardExpression(Element self) {
+        Expression result = null;
+        if (self instanceof TransitionFeatureMembership expressionMembership && expressionMembership.getOwnedMemberElement() instanceof Expression expression) {
+            result = expression;
+        } else if (self instanceof TransitionUsage transitionUsage && !transitionUsage.getGuardExpression().isEmpty()) {
+            result = transitionUsage.getGuardExpression().get(0);
+        }
+        return result;
+    }
+
     /**
      * Gets the {@link ResultExpressionMembership} from a {@link Namespace} or a {@link ResultExpressionMembership}.
      *
diff --git a/frontend/syson-components/src/extensions/expressions/ExpressionPropertySection.tsx b/frontend/syson-components/src/extensions/expressions/ExpressionPropertySection.tsx
index d9400084a..2ae67f25e 100644
--- a/frontend/syson-components/src/extensions/expressions/ExpressionPropertySection.tsx
+++ b/frontend/syson-components/src/extensions/expressions/ExpressionPropertySection.tsx
@@ -13,12 +13,12 @@
 
 import { getCSSColor } from '@eclipse-sirius/sirius-components-core';
 import {
-  GQLTextarea,
-  GQLTextfield,
+  getTextDecorationLineValue,
+  GQLLabelWidget,
+  LabelStyleProps,
   PropertySectionComponent,
   PropertySectionComponentProps,
   PropertySectionLabel,
-  TextfieldStyleProps,
 } from '@eclipse-sirius/sirius-components-forms';
 import Typography from '@mui/material/Typography';
 
@@ -29,57 +29,24 @@ import { useState } from 'react';
 import { makeStyles } from 'tss-react/mui';
 import { EditSysMLExpressionModal } from './EditSysMLExpressionModal';
 
-const useStyle = makeStyles<TextfieldStyleProps>()(
-  (theme, { backgroundColor, foregroundColor, fontSize, italic, bold, gridLayout }) => {
-    const {
-      gridTemplateColumns,
-      gridTemplateRows,
-      labelGridColumn,
-      labelGridRow,
-      widgetGridColumn,
-      widgetGridRow,
-      gap,
-    } = {
-      ...gridLayout,
-    };
-    return {
-      style: {
-        backgroundColor: backgroundColor ? getCSSColor(backgroundColor, theme) : undefined,
-        color: foregroundColor ? getCSSColor(foregroundColor, theme) : undefined,
-        fontSize: fontSize ? fontSize : undefined,
-        fontStyle: italic ? 'italic' : undefined,
-        fontWeight: bold ? 'bold' : undefined,
-      },
-      input: {
-        paddingTop: theme.spacing(0.5),
-        paddingBottom: theme.spacing(0.5),
-      },
-      textfield: {
-        marginTop: theme.spacing(0.5),
-        marginBottom: theme.spacing(0.5),
-      },
-      formControl: {},
-      propertySection: {
-        display: 'grid',
-        gridTemplateColumns,
-        gridTemplateRows,
-        alignItems: 'center',
-        gap: gap ?? '',
-      },
-      propertySectionLabel: {
-        gridColumn: labelGridColumn,
-        gridRow: labelGridRow,
-        display: 'flex',
-        flexDirection: 'row',
-        gap: theme.spacing(2),
-        alignItems: 'center',
-      },
-      propertySectionWidget: {
-        gridColumn: widgetGridColumn,
-        gridRow: widgetGridRow,
-      },
-    };
-  }
+const useStyle = makeStyles<LabelStyleProps>()(
+  (theme, { color, fontSize, italic, bold, underline, strikeThrough }) => ({
+    style: {
+      color: color ? getCSSColor(color, theme) : undefined,
+      fontSize: fontSize ? fontSize : undefined,
+      fontStyle: italic ? 'italic' : undefined,
+      fontWeight: bold ? 'bold' : undefined,
+      textDecorationLine: getTextDecorationLineValue(underline, strikeThrough),
+      verticalAlign: 'baseline',
+      alignItems: 'center',
+      display: 'flex',
+    },
+    propertySection: {
+      display: 'flex',
+      flexDirection: 'row',
+      gap: theme.spacing(2),
+    },
+  })
 );
 
 // Extracts the UUID from the string of the form "details://?objectIds=[c5f78f3a-8b39-4cb0-903a-cedd8e6e71f6]" if it contains a single UUID, otherwise returns null.
@@ -93,20 +60,18 @@ type ExpressionPropertySectionState = {
   state: 'idle' | 'modal';
 };
 
-export const ExpressionPropertySection: PropertySectionComponent<GQLTextfield | GQLTextarea> = ({
+export const ExpressionPropertySection: PropertySectionComponent<GQLLabelWidget> = ({
   editingContextId,
   formId,
   widget,
-}: PropertySectionComponentProps<GQLTextfield | GQLTextarea>) => {
-  const props: TextfieldStyleProps = {
-    backgroundColor: widget.style?.backgroundColor ?? null,
-    foregroundColor: widget.style?.foregroundColor ?? null,
+}: PropertySectionComponentProps<GQLLabelWidget>) => {
+  const props: LabelStyleProps = {
+    color: widget.style?.color ?? null,
     fontSize: widget.style?.fontSize ?? null,
     italic: widget.style?.italic ?? null,
     bold: widget.style?.bold ?? null,
     underline: widget.style?.underline ?? null,
     strikeThrough: widget.style?.strikeThrough ?? null,
-    gridLayout: widget.style?.widgetGridLayout ?? null,
   };
   const { classes } = useStyle(props);
   const [state, setState] = useState<ExpressionPropertySectionState>({
@@ -137,7 +102,7 @@ export const ExpressionPropertySection: PropertySectionComponent<GQLTextfield |
   const widgetForLabel = { ...widget, label: labelOverride };
   return (
     <div>
-      <div className={classes.propertySectionLabel}>
+      <div className={classes.propertySection}>
         <PropertySectionLabel editingContextId={editingContextId} formId={formId} widget={widgetForLabel} />
       </div>
       <div style={{ display: 'flex', flexDirection: 'row', justifyContent: 'space-between' }}>
diff --git a/frontend/syson-components/src/extensions/registry/SysONExtensionRegistry.tsx b/frontend/syson-components/src/extensions/registry/SysONExtensionRegistry.tsx
index c89a4e42b..5a3a94be3 100644
--- a/frontend/syson-components/src/extensions/registry/SysONExtensionRegistry.tsx
+++ b/frontend/syson-components/src/extensions/registry/SysONExtensionRegistry.tsx
@@ -239,7 +239,7 @@ sysONExtensionRegistry.putData(widgetContributionExtensionPoint, {
       previewComponent: () => null,
       component: (widget: GQLWidget): PropertySectionComponent<GQLWidget> | null => {
         let propertySectionComponent: PropertySectionComponent<GQLWidget> | null = null;
-        if (widget.__typename == 'Textarea' && widget.label.startsWith('syson:expression-value-widget')) {
+        if (widget.__typename == 'LabelWidget' && widget.label.startsWith('syson:expression-value-widget')) {
           propertySectionComponent = ExpressionPropertySection as PropertySectionComponent<GQLWidget>;
         }
         return propertySectionComponent;
diff --git a/integration-tests-cypress/cypress/e2e/project/details/details.cy.ts b/integration-tests-cypress/cypress/e2e/project/details/details.cy.ts
index 150ca4f8b..38e210425 100644
--- a/integration-tests-cypress/cypress/e2e/project/details/details.cy.ts
+++ b/integration-tests-cypress/cypress/e2e/project/details/details.cy.ts
@@ -110,5 +110,19 @@ describe('Details View Tests', () => {
         cy.getByTestId('details-expression-value').should('have.text', '80 [SI::centimetre]');
       });
     });
+
+    context('When we select a TransitionUsage with a guard Expression', () => {
+      beforeEach(() => {
+        explorer.select('Drive Batmobile');
+        explorer.expand('Drive Batmobile');
+        // The TransitionUsage is anonymous so select the closest named item and move down using the keyboard
+        explorer.select('scanEnvironment');
+        cy.getByTestId('scanEnvironment').type('{downArrow}{downArrow}{downArrow}');
+      });
+      it("Then the Details view shows the child expression's textual value", () => {
+        cy.getByTestId('details-expression-value').should('exist');
+        cy.getByTestId('details-expression-value').should('have.text', 'scanEnvironment.status == StatusKind::safe');
+      });
+    });
   });
 });