diff --git a/src/inputs.ts b/src/inputs.ts
index 66b945fe..5dfcdc4a 100644
--- a/src/inputs.ts
+++ b/src/inputs.ts
@@ -963,7 +963,11 @@ export default class Inputs {
       'sections',
       inputContext.sections ?? (this.config.get('sections') as ReadmeSection[]),
     );
-    this.sections = this.config.get('sections') as ReadmeSection[];
+    const configuredSections: unknown = this.config.get('sections');
+    if (!Array.isArray(configuredSections) || !configuredSections.every((section: unknown) => typeof section === 'string')) {
+      throw new Error('Invalid sections configuration: expected an array of section names');
+    }
+    this.sections = configuredSections as ReadmeSection[];
     this.readmePath =
       inputContext.readmePath ?? path.resolve(this.config.get(ConfigKeys.pathsReadme) as string);
     this.readmeEditor = inputContext.readmeEditor ?? new ReadmeEditor(this.readmePath);