diff --git a/dist/index.js b/dist/index.js
index 5963160..aceca09 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -35,6 +35,13 @@ async function run(dependencies = {}) {
 
     if (errorOutput) {
       core.warning(`govulncheck stderr: ${errorOutput}`);
+      
+      // Check for critical errors that indicate govulncheck couldn't run properly
+      if (errorOutput.includes('missing go.sum entry') || 
+          errorOutput.includes('could not import') ||
+          errorOutput.includes('invalid package name')) {
+        throw new Error(`govulncheck failed due to missing dependencies. Please run 'go mod tidy' to update go.mod and go.sum files.\n\nError: ${errorOutput}`);
+      }
     }
 
     // Log raw output for debugging
diff --git a/index.js b/index.js
index 96a33a7..2fffab8 100644
--- a/index.js
+++ b/index.js
@@ -29,6 +29,13 @@ async function run(dependencies = {}) {
 
     if (errorOutput) {
       core.warning(`govulncheck stderr: ${errorOutput}`);
+      
+      // Check for critical errors that indicate govulncheck couldn't run properly
+      if (errorOutput.includes('missing go.sum entry') || 
+          errorOutput.includes('could not import') ||
+          errorOutput.includes('invalid package name')) {
+        throw new Error(`govulncheck failed due to missing dependencies. Please run 'go mod tidy' to update go.mod and go.sum files.\n\nError: ${errorOutput}`);
+      }
     }
 
     // Log raw output for debugging
diff --git a/test/index.test.js b/test/index.test.js
index 5d3ee04..d6b63cb 100644
--- a/test/index.test.js
+++ b/test/index.test.js
@@ -174,6 +174,34 @@ describe('GitHub Action Integration', () => {
     );
   });
 
+  it('should fail when go.sum is missing', async () => {
+    mockGovulncheck.run.mockResolvedValue({
+      output: '{"config": {}}',
+      errorOutput: 'missing go.sum entry for module providing package golang.org/x/net/html',
+      exitCode: 1
+    });
+
+    await expect(run({
+      govulncheck: mockGovulncheck,
+      parser: mockParser,
+      annotator: mockAnnotator
+    })).rejects.toThrow('govulncheck failed due to missing dependencies');
+  });
+
+  it('should fail when imports cannot be resolved', async () => {
+    mockGovulncheck.run.mockResolvedValue({
+      output: '{"config": {}}',
+      errorOutput: 'could not import golang.org/x/net/html (invalid package name: "")',
+      exitCode: 1
+    });
+
+    await expect(run({
+      govulncheck: mockGovulncheck,
+      parser: mockParser,
+      annotator: mockAnnotator
+    })).rejects.toThrow('govulncheck failed due to missing dependencies');
+  });
+
   it('should handle errors and set action as failed', async () => {
     const error = new Error('Failed to install govulncheck');
     mockGovulncheck.install.mockRejectedValue(error);