diff --git a/.changeset/brown-days-pretend.md b/.changeset/brown-days-pretend.md
new file mode 100644
index 0000000000..4b6a328724
--- /dev/null
+++ b/.changeset/brown-days-pretend.md
@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-tech-insights': patch
+---
+
+Fixed bug when sending data by Post in `runChecks` and `runBulkChecks` functions of the `TechInsightsClient` class, the default `Content-Type` used was `plain/text`
diff --git a/plugins/tech-insights/src/api/TechInsightsClient.ts b/plugins/tech-insights/src/api/TechInsightsClient.ts
index 9bdeb119f9..6e85769b34 100644
--- a/plugins/tech-insights/src/api/TechInsightsClient.ts
+++ b/plugins/tech-insights/src/api/TechInsightsClient.ts
@@ -105,14 +105,18 @@ export class TechInsightsClient implements TechInsightsApi {
     const url = await this.discoveryApi.getBaseUrl('tech-insights');
     const { token } = await this.identityApi.getCredentials();
 
-    const request = new Request(`${url}${path}`, init);
-    if (!request.headers.has('content-type')) {
-      request.headers.set('content-type', 'application/json');
-    }
-    if (token && !request.headers.has('authorization')) {
-      request.headers.set('authorization', `Bearer ${token}`);
+    const headers: HeadersInit = new Headers(init?.headers);
+    if (!headers.has('content-type'))
+      headers.set('content-type', 'application/json');
+    if (token && !headers.has('authorization')) {
+      headers.set('authorization', `Bearer ${token}`);
     }
 
+    const request = new Request(`${url}${path}`, {
+      ...init,
+      headers,
+    });
+
     return fetch(request).then(async response => {
       if (!response.ok) {
         throw await ResponseError.fromResponse(response);