diff --git a/.changeset/brave-doors-glow.md b/.changeset/brave-doors-glow.md
new file mode 100644
index 000000000..f9e581e46
--- /dev/null
+++ b/.changeset/brave-doors-glow.md
@@ -0,0 +1,5 @@
+---
+"@gitbook/react-openapi": patch
+---
+
+Handle non-array required field in OpenAPI schema to fix TypeError with specs using boolean required values
diff --git a/packages/react-openapi/src/OpenAPISchema.test.ts b/packages/react-openapi/src/OpenAPISchema.test.ts
index 8f7c10e9c..1def1780e 100644
--- a/packages/react-openapi/src/OpenAPISchema.test.ts
+++ b/packages/react-openapi/src/OpenAPISchema.test.ts
@@ -185,6 +185,60 @@ describe('getSchemaAlternatives', () => {
         });
     });
 
+    it('should handle non-standard boolean required values without throwing', () => {
+        // Some specs (e.g. Trustly) use `"required": true` on properties
+        // instead of the standard `string[]` format. This should not throw.
+        const schema = {
+            allOf: [
+                {
+                    type: 'object',
+                    properties: {
+                        name: { type: 'string' },
+                    },
+                    required: true as any,
+                },
+                {
+                    type: 'object',
+                    properties: {
+                        email: { type: 'string' },
+                    },
+                    required: ['email'],
+                },
+            ],
+        } as any;
+
+        const result = getSchemaAlternatives(schema);
+        expect(result).toBeDefined();
+        // The boolean `required: true` should be ignored, only the valid array is kept
+        expect(result?.schemas[0]?.required).toEqual(['email']);
+    });
+
+    it('should handle boolean required on both schemas without throwing', () => {
+        const schema = {
+            allOf: [
+                {
+                    type: 'object',
+                    properties: {
+                        name: { type: 'string' },
+                    },
+                    required: true as any,
+                },
+                {
+                    type: 'object',
+                    properties: {
+                        email: { type: 'string' },
+                    },
+                    required: false as any,
+                },
+            ],
+        } as any;
+
+        const result = getSchemaAlternatives(schema);
+        expect(result).toBeDefined();
+        // Boolean required values should not cause a crash, result is an empty array
+        expect(result?.schemas[0]?.required).toEqual([]);
+    });
+
     describe('safe merging with allOf', () => {
         it('should merge objects with safe extensions', () => {
             expect(
diff --git a/packages/react-openapi/src/OpenAPISchema.tsx b/packages/react-openapi/src/OpenAPISchema.tsx
index e070681f4..67f3a9768 100644
--- a/packages/react-openapi/src/OpenAPISchema.tsx
+++ b/packages/react-openapi/src/OpenAPISchema.tsx
@@ -1105,15 +1105,19 @@ function mergeRequiredFields(
     schemaOrRef: OpenAPIV3.SchemaObject | OpenAPIV3.ReferenceObject,
     latestAncestor: OpenAPIV3.SchemaObject | undefined
 ) {
-    if (!schemaOrRef.required && !latestAncestor?.required) {
+    const ancestorRequired = Array.isArray(latestAncestor?.required)
+        ? latestAncestor.required
+        : undefined;
+
+    if (checkIsReference(schemaOrRef)) {
+        return ancestorRequired;
+    }
+
+    const schemaRequired = Array.isArray(schemaOrRef.required) ? schemaOrRef.required : undefined;
+
+    if (!ancestorRequired && !schemaRequired) {
         return undefined;
     }
 
-    if (checkIsReference(schemaOrRef)) {
-        return latestAncestor?.required;
-    }
-
-    return Array.from(
-        new Set([...(latestAncestor?.required || []), ...(schemaOrRef.required || [])])
-    );
+    return Array.from(new Set([...(ancestorRequired || []), ...(schemaRequired || [])]));
 }