diff --git a/src/cli/commands/monitor/formatters/format-monitor-response.ts b/src/cli/commands/monitor/formatters/format-monitor-response.ts
index aa700598a39..0fb49ef0e58 100644
--- a/src/cli/commands/monitor/formatters/format-monitor-response.ts
+++ b/src/cli/commands/monitor/formatters/format-monitor-response.ts
@@ -15,7 +15,8 @@ export function formatMonitorOutput(
   const manageUrl = buildManageUrl(res.id, res.org);
   const advertiseGradleSubProjectsCount =
     packageManager === 'gradle' && !options['gradle-sub-project'];
-
+  const advertiseAllProjectsCount =
+    packageManager !== 'gradle' && !options.allProjects && foundProjectCount;
   const issues = res.licensesPolicy ? 'issues' : 'vulnerabilities';
   const humanReadableName = projectName
     ? `${res.path} (${projectName})`
@@ -31,6 +32,12 @@ export function formatMonitorOutput(
             'use --all-sub-projects flag to scan all sub-projects.\n\n',
         )
       : '') +
+    (advertiseAllProjectsCount && foundProjectCount
+      ? chalk.bold.white(
+          `Tip: Detected multiple supported manifests (${foundProjectCount}), ` +
+            'use --all-projects to scan all of them at once.\n\n',
+        )
+      : '') +
     (res.isMonitored
       ? 'Notifications about newly disclosed ' +
         issues +
diff --git a/src/cli/commands/monitor/index.ts b/src/cli/commands/monitor/index.ts
index e6795a7b095..283fe871bfe 100644
--- a/src/cli/commands/monitor/index.ts
+++ b/src/cli/commands/monitor/index.ts
@@ -28,7 +28,7 @@ import { processJsonMonitorResponse } from './process-json-monitor';
 import snyk = require('../../../lib'); // TODO(kyegupov): fix import
 import { formatMonitorOutput } from './formatters/format-monitor-response';
 import { getDepsFromPlugin } from '../../../lib/plugins/get-deps-from-plugin';
-import { getSubProjectCount } from '../../../lib/plugins/get-sub-project-count';
+import { getExtraProjectCount } from '../../../lib/plugins/get-extra-project-count';
 import { extractPackageManager } from '../../../lib/plugins/extract-package-manager';
 import { MultiProjectResultCustom } from '../../../lib/plugins/get-multi-plugin-result';
 import { convertMultiResultToMultiCustom } from '../../../lib/plugins/convert-multi-plugin-res-to-multi-custom';
@@ -241,7 +241,7 @@ async function monitor(...args0: MethodArgs): Promise<any> {
             res,
             options,
             projectName,
-            getSubProjectCount(inspectResult),
+            await getExtraProjectCount(path, options, inspectResult),
           );
           // push a good result
           results.push({ ok: true, data: monOutput, path, projectName });
diff --git a/src/cli/commands/test/index.ts b/src/cli/commands/test/index.ts
index 96963e12bd2..02971c1520c 100644
--- a/src/cli/commands/test/index.ts
+++ b/src/cli/commands/test/index.ts
@@ -215,7 +215,6 @@ async function test(...args: MethodArgs): Promise<TestCommandResult> {
   let response = results
     .map((result, i) => {
       resultOptions[i].pinningSupported = pinningSupported;
-
       return displayResult(
         results[i] as LegacyVulnApiResult,
         resultOptions[i],
@@ -425,13 +424,23 @@ function displayResult(
   let multiProjAdvice = '';
 
   const advertiseGradleSubProjectsCount =
-    projectType === 'gradle' && !options['gradle-sub-project'];
-  if (advertiseGradleSubProjectsCount && foundProjectCount) {
+    projectType === 'gradle' &&
+    !options['gradle-sub-project'] &&
+    foundProjectCount;
+  if (advertiseGradleSubProjectsCount) {
     multiProjAdvice = chalk.bold.white(
       `\n\nTip: This project has multiple sub-projects (${foundProjectCount}), ` +
         'use --all-sub-projects flag to scan all sub-projects.',
     );
   }
+  const advertiseAllProjectsCount =
+    projectType !== 'gradle' && !options.allProjects && foundProjectCount;
+  if (advertiseAllProjectsCount) {
+    multiProjAdvice = chalk.bold.white(
+      `\n\nTip: Detected multiple supported manifests (${foundProjectCount}), ` +
+        'use --all-projects to scan all of them at once.',
+    );
+  }
 
   // OK  => no vulns found, return
   if (res.ok && res.vulnerabilities.length === 0) {
diff --git a/src/lib/plugins/get-extra-project-count.ts b/src/lib/plugins/get-extra-project-count.ts
new file mode 100644
index 00000000000..8c40a71d7d0
--- /dev/null
+++ b/src/lib/plugins/get-extra-project-count.ts
@@ -0,0 +1,29 @@
+import { legacyPlugin as pluginApi } from '@snyk/cli-interface';
+import { find } from '../find-files';
+import { AUTO_DETECTABLE_FILES } from '../detect';
+import { Options } from '../types';
+
+export async function getExtraProjectCount(
+  root: string,
+  options: Options,
+  inspectResult: pluginApi.InspectResult,
+): Promise<number | undefined> {
+  if (options.docker) {
+    return undefined;
+  }
+  if (
+    inspectResult.plugin.meta &&
+    inspectResult.plugin.meta.allSubProjectNames &&
+    inspectResult.plugin.meta.allSubProjectNames.length > 1
+  ) {
+    return inspectResult.plugin.meta.allSubProjectNames.length;
+  }
+  try {
+    const extraTargetFiles = await find(root, [], AUTO_DETECTABLE_FILES);
+    const foundProjectsCount =
+      extraTargetFiles.length > 1 ? extraTargetFiles.length - 1 : undefined;
+    return foundProjectsCount;
+  } catch (e) {
+    return undefined;
+  }
+}
diff --git a/src/lib/plugins/get-sub-project-count.ts b/src/lib/plugins/get-sub-project-count.ts
deleted file mode 100644
index 5b11ae61675..00000000000
--- a/src/lib/plugins/get-sub-project-count.ts
+++ /dev/null
@@ -1,15 +0,0 @@
-import { legacyPlugin as pluginApi } from '@snyk/cli-interface';
-
-export function getSubProjectCount(
-  inspectResult: pluginApi.InspectResult,
-): number | undefined {
-  if (
-    inspectResult.plugin.meta &&
-    inspectResult.plugin.meta.allSubProjectNames &&
-    inspectResult.plugin.meta.allSubProjectNames.length > 1
-  ) {
-    return inspectResult.plugin.meta.allSubProjectNames.length;
-  }
-
-  return undefined;
-}
diff --git a/src/lib/snyk-test/run-test.ts b/src/lib/snyk-test/run-test.ts
index 9ebaf3a960f..ca6b6141259 100644
--- a/src/lib/snyk-test/run-test.ts
+++ b/src/lib/snyk-test/run-test.ts
@@ -47,7 +47,7 @@ import { ScannedProjectCustom } from '../plugins/get-multi-plugin-result';
 import request = require('../request');
 import spinner = require('../spinner');
 import { extractPackageManager } from '../plugins/extract-package-manager';
-import { getSubProjectCount } from '../plugins/get-sub-project-count';
+import { getExtraProjectCount } from '../plugins/get-extra-project-count';
 import { serializeCallGraphWithMetrics } from '../reachable-vulns';
 import { validateOptions } from '../options-validator';
 import { findAndLoadPolicy } from '../policy';
@@ -471,7 +471,7 @@ async function assembleLocalPayloads(
         projectNameOverride: options.projectName,
         originalProjectName,
         policy: policy ? policy.toString() : undefined,
-        foundProjectCount: getSubProjectCount(deps),
+        foundProjectCount: await getExtraProjectCount(root, options, deps),
         displayTargetFile: targetFile,
         docker: (pkg as DepTree).docker,
         hasDevDependencies: (pkg as any).hasDevDependencies,
diff --git a/test/acceptance/cli-monitor/cli-monitor.acceptance.test.ts b/test/acceptance/cli-monitor/cli-monitor.acceptance.test.ts
index a2a2449d93d..f31388744ea 100644
--- a/test/acceptance/cli-monitor/cli-monitor.acceptance.test.ts
+++ b/test/acceptance/cli-monitor/cli-monitor.acceptance.test.ts
@@ -1370,6 +1370,12 @@ test('`monitor cocoapods-app --file=Podfile`', async (t) => {
   );
 });
 
+test('`monitor large-mono-repo --file=bundler-app/Gemfile` suggest to use --all-projects', async (t) => {
+  chdirWorkspaces('large-mono-repo');
+  const res = await cli.monitor({ file: 'bundler-app/Gemfile' });
+  t.match(res, '--all-projects', 'Suggest using --all-projects');
+});
+
 test('`monitor cocoapods-app --file=Podfile.lock`', async (t) => {
   chdirWorkspaces('cocoapods-app');
   const plugin = {
diff --git a/test/acceptance/cli-test/cli-test.ruby.spec.ts b/test/acceptance/cli-test/cli-test.ruby.spec.ts
index e765337cedc..5c86cbb794d 100644
--- a/test/acceptance/cli-test/cli-test.ruby.spec.ts
+++ b/test/acceptance/cli-test/cli-test.ruby.spec.ts
@@ -568,5 +568,19 @@ export const RubyTests: AcceptanceTests = {
         );
       }
     },
+    '`test large-mono-repo --file=bundler-app/Gemfile`': (
+      params,
+      utils,
+    ) => async (t) => {
+      utils.chdirWorkspaces();
+      const res = await params.cli.test('large-mono-repo', {
+        file: 'bundler-app/Gemfile',
+      });
+      t.match(
+        res.getDisplayResults(),
+        '--all-projects',
+        'Suggest using --all-projects',
+      );
+    },
   },
 };