diff --git a/.changeset/moody-windows-type.md b/.changeset/moody-windows-type.md
new file mode 100644
index 00000000000..abd6b313331
--- /dev/null
+++ b/.changeset/moody-windows-type.md
@@ -0,0 +1,5 @@
+---
+'@graphql-codegen/client-preset': patch
+---
+
+Add warning and errors to prevent unwanted configuration
diff --git a/dev-test/codegen.ts b/dev-test/codegen.ts
index 6d2d736e48a..da56ea74e28 100644
--- a/dev-test/codegen.ts
+++ b/dev-test/codegen.ts
@@ -326,7 +326,7 @@ const config: CodegenConfig = {
       preset: 'gql-tag-operations-preset',
       plugins: [],
     },
-    './dev-test/gql-tag-operations/graphql': {
+    './dev-test/gql-tag-operations/graphql/': {
       schema: './dev-test/gql-tag-operations/schema.graphql',
       documents: './dev-test/gql-tag-operations/src/**/*.ts',
       preset: 'client',
diff --git a/packages/presets/client/src/index.ts b/packages/presets/client/src/index.ts
index 21295897fda..4e28dd44686 100644
--- a/packages/presets/client/src/index.ts
+++ b/packages/presets/client/src/index.ts
@@ -64,9 +64,19 @@ export type ClientPresetConfig = {
   gqlTagName?: string;
 };
 
+const isOutputFolderLike = (baseOutputDir: string) => baseOutputDir.endsWith('/');
+
 export const preset: Types.OutputPreset<ClientPresetConfig> = {
   prepareDocuments: (outputFilePath, outputSpecificDocuments) => [...outputSpecificDocuments, `!${outputFilePath}`],
   buildGeneratesSection: options => {
+    if (!isOutputFolderLike(options.baseOutputDir)) {
+      throw new Error('[client-preset] target output should be a directory, ex: "src/gql/"');
+    }
+
+    if (options.plugins.length > 0) {
+      throw new Error('[client-preset] providing `plugins` with `preset: "client" leads to duplicated generated types');
+    }
+
     const reexports: Array<string> = [];
 
     // the `client` preset is restricting the config options inherited from `typescript`, `typescript-operations` and others.
@@ -139,7 +149,7 @@ export const preset: Types.OutputPreset<ClientPresetConfig> = {
       reexports.push('fragment-masking');
 
       fragmentMaskingFileGenerateConfig = {
-        filename: `${options.baseOutputDir}/fragment-masking${fragmentMaskingArtifactFileExtension}`,
+        filename: `${options.baseOutputDir}fragment-masking${fragmentMaskingArtifactFileExtension}`,
         pluginMap: {
           [`fragment-masking`]: fragmentMaskingPlugin,
         },
@@ -163,7 +173,7 @@ export const preset: Types.OutputPreset<ClientPresetConfig> = {
 
     if (reexports.length) {
       indexFileGenerateConfig = {
-        filename: `${options.baseOutputDir}/index.ts`,
+        filename: `${options.baseOutputDir}index.ts`,
         pluginMap: {
           [`add`]: addPlugin,
         },
@@ -182,7 +192,7 @@ export const preset: Types.OutputPreset<ClientPresetConfig> = {
 
     return [
       {
-        filename: `${options.baseOutputDir}/graphql.ts`,
+        filename: `${options.baseOutputDir}graphql.ts`,
         plugins,
         pluginMap,
         schema: options.schema,
@@ -193,7 +203,7 @@ export const preset: Types.OutputPreset<ClientPresetConfig> = {
         documents: sources,
       },
       {
-        filename: `${options.baseOutputDir}/gql${gqlArtifactFileExtension}`,
+        filename: `${options.baseOutputDir}gql${gqlArtifactFileExtension}`,
         plugins: genDtsPlugins,
         pluginMap,
         schema: options.schema,
diff --git a/packages/presets/client/src/process-sources.ts b/packages/presets/client/src/process-sources.ts
index 2b5337b6dd9..ac7ecd96dba 100644
--- a/packages/presets/client/src/process-sources.ts
+++ b/packages/presets/client/src/process-sources.ts
@@ -15,7 +15,13 @@ export function processSources(sources: Array<Source>, buildName: BuildNameFunct
     for (const definition of document?.definitions ?? []) {
       if (definition?.kind !== `OperationDefinition` && definition?.kind !== 'FragmentDefinition') continue;
 
-      if (definition.name?.kind !== `Name`) continue;
+      if (definition.name?.kind !== `Name`) {
+        if (definition?.kind === `OperationDefinition`) {
+          // eslint-disable-next-line no-console
+          console.warn(`[client-preset] the following anonymous operation is skipped: ${source.rawSDL}`);
+        }
+        continue;
+      }
 
       operations.push({
         initialName: buildName(definition),
diff --git a/packages/presets/client/tests/client-preset.spec.ts b/packages/presets/client/tests/client-preset.spec.ts
index b6fdbefd7f1..daf3525c1ee 100644
--- a/packages/presets/client/tests/client-preset.spec.ts
+++ b/packages/presets/client/tests/client-preset.spec.ts
@@ -2,7 +2,7 @@ import { executeCodegen } from '@graphql-codegen/cli';
 import { mergeOutputs } from '@graphql-codegen/plugin-helpers';
 import '@graphql-codegen/testing';
 import { validateTs } from '@graphql-codegen/testing';
-import { readFileSync } from 'fs';
+import * as fs from 'fs';
 import path from 'path';
 import { preset } from '../src/index.js';
 
@@ -20,7 +20,7 @@ describe('client-preset', () => {
       ],
       documents: path.join(__dirname, 'fixtures/simple-uppercase-operation-name.ts'),
       generates: {
-        out1: {
+        'out1/': {
           preset,
           plugins: [],
         },
@@ -76,7 +76,7 @@ export * from "./fragment-masking"`);
       ],
       documents: path.join(__dirname, 'fixtures/simple-lowercase-operation-name.ts'),
       generates: {
-        out1: {
+        'out1/': {
           preset,
           plugins: [],
         },
@@ -132,7 +132,7 @@ export * from "./fragment-masking"`);
       ],
       documents: path.join(__dirname, 'fixtures/crlf-operation.ts'),
       generates: {
-        out1: {
+        'out1/': {
           preset,
           plugins: [],
         },
@@ -176,7 +176,7 @@ export * from "./fragment-masking"`);
       ],
       documents: path.join(__dirname, 'fixtures/simple-uppercase-operation-name.ts'),
       generates: {
-        out1: {
+        'out1/': {
           preset,
           plugins: [],
         },
@@ -271,7 +271,7 @@ export * from "./fragment-masking"`);
       ],
       documents: path.join(__dirname, 'fixtures/duplicate-operation.ts'),
       generates: {
-        out1: {
+        'out1/': {
           preset,
           plugins: [],
         },
@@ -350,7 +350,7 @@ export * from "./fragment-masking"`);
         ],
         documents: path.join(__dirname, 'fixtures/simple-uppercase-operation-name.ts'),
         generates: {
-          out1: {
+          'out1/': {
             preset,
             plugins: [],
             presetConfig: {
@@ -406,7 +406,7 @@ export * from "./fragment-masking"`);
         ],
         documents: path.join(__dirname, 'fixtures/simple-uppercase-operation-name.ts'),
         generates: {
-          out1: {
+          'out1/': {
             preset,
             plugins: [],
             presetConfig: {
@@ -432,7 +432,7 @@ export * from "./fragment-masking"`);
         ],
         documents: path.join(__dirname, 'fixtures/simple-uppercase-operation-name.ts'),
         generates: {
-          out1: {
+          'out1/': {
             preset,
             plugins: [],
             presetConfig: {
@@ -541,7 +541,7 @@ export * from "./fragment-masking"`);
         ],
         documents: docPath,
         generates: {
-          out1: {
+          'out1/': {
             preset,
             plugins: [],
             presetConfig: {
@@ -553,7 +553,7 @@ export * from "./fragment-masking"`);
 
       const content = mergeOutputs([
         ...result,
-        readFileSync(docPath, 'utf8'),
+        fs.readFileSync(docPath, 'utf8'),
         `
         function App(props: { data: FooQuery }) {
           const fragment: FooFragment | null | undefined = useFragment(Fragment, props.data.foo);
@@ -581,7 +581,7 @@ export * from "./fragment-masking"`);
         ],
         documents: docPath,
         generates: {
-          out1: {
+          'out1/': {
             preset,
             plugins: [],
             presetConfig: {
@@ -593,7 +593,7 @@ export * from "./fragment-masking"`);
 
       const content = mergeOutputs([
         ...result,
-        readFileSync(docPath, 'utf8'),
+        fs.readFileSync(docPath, 'utf8'),
         `
         function App(props: { data: FoosQuery }) {
           const fragments: ReadonlyArray<FooFragment> | null | undefined = useFragment(Fragment, props.data.foos);
@@ -618,7 +618,7 @@ export * from "./fragment-masking"`);
       ],
       documents: path.join(__dirname, 'fixtures/simple-uppercase-operation-name.ts'),
       generates: {
-        out1: {
+        'out1/': {
           preset,
           plugins: [],
         },
@@ -675,7 +675,7 @@ export * from "./fragment-masking.js"`);
           `,
         ],
         generates: {
-          out1: {
+          'out1/': {
             preset,
             plugins: [],
           },