diff --git a/.changeset/smooth-deers-melt.md b/.changeset/smooth-deers-melt.md
new file mode 100644
index 0000000000..9757de5181
--- /dev/null
+++ b/.changeset/smooth-deers-melt.md
@@ -0,0 +1,5 @@
+---
+'@backstage/config-loader': patch
+---
+
+Include `devDependencies` and `optionalDependencies` in the detection of Backstage packages when collecting configuration schema.
diff --git a/packages/config-loader/src/lib/schema/collect.test.ts b/packages/config-loader/src/lib/schema/collect.test.ts
index 479e63c94c..ef9d38faa9 100644
--- a/packages/config-loader/src/lib/schema/collect.test.ts
+++ b/packages/config-loader/src/lib/schema/collect.test.ts
@@ -87,6 +87,8 @@ describe('collectConfigSchemas', () => {
             dependencies: {
               c1: '0.0.0',
               c2: '0.0.0',
+            },
+            devDependencies: {
               '@backstage/mock': '0.0.0',
             },
             configSchema: { ...mockSchema, title: 'b' },
diff --git a/packages/config-loader/src/lib/schema/collect.ts b/packages/config-loader/src/lib/schema/collect.ts
index b53389d499..b363e8e5f3 100644
--- a/packages/config-loader/src/lib/schema/collect.ts
+++ b/packages/config-loader/src/lib/schema/collect.ts
@@ -74,6 +74,8 @@ export async function collectConfigSchemas(
     const pkg = await fs.readJson(pkgPath);
     const depNames = [
       ...Object.keys(pkg.dependencies ?? {}),
+      ...Object.keys(pkg.devDependencies ?? {}),
+      ...Object.keys(pkg.optionalDependencies ?? {}),
       ...Object.keys(pkg.peerDependencies ?? {}),
     ];
 
diff --git a/packages/integration/src/azure/config.test.ts b/packages/integration/src/azure/config.test.ts
index d43536cf47..385086fbcf 100644
--- a/packages/integration/src/azure/config.test.ts
+++ b/packages/integration/src/azure/config.test.ts
@@ -30,9 +30,18 @@ describe('readAzureIntegrationConfig', () => {
   async function buildFrontendConfig(
     data: Partial<AzureIntegrationConfig>,
   ): Promise<Config> {
-    const schema = await loadConfigSchema({
+    const fullSchema = await loadConfigSchema({
       dependencies: [require('../../package.json').name],
     });
+    const serializedSchema = fullSchema.serialize() as {
+      schemas: { path: string }[];
+    };
+    const schema = await loadConfigSchema({
+      serialized: {
+        ...serializedSchema, // grab the schema from this package only
+        schemas: serializedSchema.schemas.filter(s => s.path === 'config.d.ts'),
+      },
+    });
     const processed = schema.process(
       [{ data: { integrations: { azure: [data] } }, context: 'app' }],
       { visibility: ['frontend'] },
diff --git a/packages/integration/src/bitbucket/config.test.ts b/packages/integration/src/bitbucket/config.test.ts
index f3d076e1b6..b887566e35 100644
--- a/packages/integration/src/bitbucket/config.test.ts
+++ b/packages/integration/src/bitbucket/config.test.ts
@@ -30,9 +30,18 @@ describe('readBitbucketIntegrationConfig', () => {
   async function buildFrontendConfig(
     data: Partial<BitbucketIntegrationConfig>,
   ): Promise<Config> {
-    const schema = await loadConfigSchema({
+    const fullSchema = await loadConfigSchema({
       dependencies: [require('../../package.json').name],
     });
+    const serializedSchema = fullSchema.serialize() as {
+      schemas: { path: string }[];
+    };
+    const schema = await loadConfigSchema({
+      serialized: {
+        ...serializedSchema, // grab the schema from this package only
+        schemas: serializedSchema.schemas.filter(s => s.path === 'config.d.ts'),
+      },
+    });
     const processed = schema.process(
       [{ data: { integrations: { bitbucket: [data] } }, context: 'app' }],
       { visibility: ['frontend'] },
diff --git a/packages/integration/src/github/config.test.ts b/packages/integration/src/github/config.test.ts
index 10d076f85d..eb084b14a9 100644
--- a/packages/integration/src/github/config.test.ts
+++ b/packages/integration/src/github/config.test.ts
@@ -30,9 +30,18 @@ describe('readGitHubIntegrationConfig', () => {
   async function buildFrontendConfig(
     data: Partial<GitHubIntegrationConfig>,
   ): Promise<Config> {
-    const schema = await loadConfigSchema({
+    const fullSchema = await loadConfigSchema({
       dependencies: [require('../../package.json').name],
     });
+    const serializedSchema = fullSchema.serialize() as {
+      schemas: { path: string }[];
+    };
+    const schema = await loadConfigSchema({
+      serialized: {
+        ...serializedSchema, // grab the schema from this package only
+        schemas: serializedSchema.schemas.filter(s => s.path === 'config.d.ts'),
+      },
+    });
     const processed = schema.process(
       [{ data: { integrations: { github: [data] } }, context: 'app' }],
       { visibility: ['frontend'] },
diff --git a/packages/integration/src/gitlab/config.test.ts b/packages/integration/src/gitlab/config.test.ts
index 4c235ff668..1308704e9d 100644
--- a/packages/integration/src/gitlab/config.test.ts
+++ b/packages/integration/src/gitlab/config.test.ts
@@ -30,9 +30,18 @@ describe('readGitLabIntegrationConfig', () => {
   async function buildFrontendConfig(
     data: Partial<GitLabIntegrationConfig>,
   ): Promise<Config> {
-    const schema = await loadConfigSchema({
+    const fullSchema = await loadConfigSchema({
       dependencies: [require('../../package.json').name],
     });
+    const serializedSchema = fullSchema.serialize() as {
+      schemas: { path: string }[];
+    };
+    const schema = await loadConfigSchema({
+      serialized: {
+        ...serializedSchema, // grab the schema from this package only
+        schemas: serializedSchema.schemas.filter(s => s.path === 'config.d.ts'),
+      },
+    });
     const processed = schema.process(
       [{ data: { integrations: { gitlab: [data] } }, context: 'app' }],
       { visibility: ['frontend'] },