diff --git a/src/legacy/server/csp/index.test.ts b/src/legacy/server/csp/index.test.ts
index 9586166b65641..c11c3cd2d6e1b 100644
--- a/src/legacy/server/csp/index.test.ts
+++ b/src/legacy/server/csp/index.test.ts
@@ -39,12 +39,13 @@ import {
 // the nature of a change in defaults during a PR review.
 test('default CSP rules', () => {
   expect(DEFAULT_CSP_RULES).toMatchInlineSnapshot(`
-Array [
-  "script-src 'unsafe-eval' 'nonce-{nonce}'",
-  "worker-src blob:",
-  "child-src blob:",
-]
-`);
+    Array [
+      "script-src 'unsafe-eval' 'nonce-{nonce}'",
+      "worker-src blob:",
+      "child-src blob:",
+      "style-src 'unsafe-inline' 'self'",
+    ]
+  `);
 });
 
 test('CSP strict mode defaults to disabled', () => {
diff --git a/src/legacy/server/csp/index.ts b/src/legacy/server/csp/index.ts
index 96c359e61e25b..d0b626e3fa2cc 100644
--- a/src/legacy/server/csp/index.ts
+++ b/src/legacy/server/csp/index.ts
@@ -26,6 +26,7 @@ export const DEFAULT_CSP_RULES = Object.freeze([
   `script-src 'unsafe-eval' 'nonce-{nonce}'`,
   'worker-src blob:',
   'child-src blob:',
+  `style-src 'unsafe-inline' 'self'`,
 ]);
 
 export const DEFAULT_CSP_STRICT = false;
diff --git a/test/api_integration/apis/general/csp.js b/test/api_integration/apis/general/csp.js
index f3501aa55adaa..8c28d7e6d7dd9 100644
--- a/test/api_integration/apis/general/csp.js
+++ b/test/api_integration/apis/general/csp.js
@@ -27,13 +27,27 @@ export default function ({ getService }) {
       const response = await supertest.get('/app/kibana');
 
       expect(response.headers).to.have.property('content-security-policy');
-    });
+      const header = response.headers['content-security-policy'];
+      const parsed = new Map(header.split(';').map(rule => {
+        const parts = rule.trim().split(' ');
+        const key = parts.splice(0, 1)[0];
+        return [key, parts];
+      }));
 
-    it('csp header does not allow all inline scripts', async () => {
-      const response = await supertest.get('/app/kibana');
+      // ensure script-src uses a nonce, and remove it so we can .eql everything else
+      const scriptSrc = parsed.get('script-src');
+      expect(scriptSrc).to.be.an(Array);
+      const nonceIndex = scriptSrc.findIndex(value => value.startsWith(`'nonce-`));
+      expect(nonceIndex).greaterThan(-1);
+      scriptSrc.splice(nonceIndex, 1);
 
-      expect(response.headers['content-security-policy']).to.contain('script-src');
-      expect(response.headers['content-security-policy']).not.to.contain('unsafe-inline');
+      const entries = Array.from(parsed.entries());
+      expect(entries).to.eql([
+        [ 'script-src', [ '\'unsafe-eval\'' ] ],
+        [ 'worker-src', [ 'blob:' ] ],
+        [ 'child-src', [ 'blob:' ] ],
+        [ 'style-src', [ '\'unsafe-inline\'', '\'self\'' ] ]
+      ]);
     });
   });
 }
diff --git a/x-pack/test/oidc_api_integration/apis/implicit_flow/oidc_auth.ts b/x-pack/test/oidc_api_integration/apis/implicit_flow/oidc_auth.ts
index 613f10054fd84..4d377f974b845 100644
--- a/x-pack/test/oidc_api_integration/apis/implicit_flow/oidc_auth.ts
+++ b/x-pack/test/oidc_api_integration/apis/implicit_flow/oidc_auth.ts
@@ -53,7 +53,7 @@ export default function({ getService }: FtrProviderContext) {
         expect(response.headers['content-type']).to.be('text/html; charset=utf-8');
         expect(response.headers['cache-control']).to.be('private, no-cache, no-store');
         expect(response.headers['content-security-policy']).to.be(
-          `script-src 'unsafe-eval' 'nonce-${scriptNonce}'; worker-src blob:; child-src blob:`
+          `script-src 'unsafe-eval' 'nonce-${scriptNonce}'; worker-src blob:; child-src blob:; style-src 'unsafe-inline' 'self'`
         );
 
         // Check that script that forwards URL fragment worked correctly.