diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7d07023..ac50e04 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,3 +12,5 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * Multiple SSH keys can now be provided (#14, closes #7). Thanks to
   @webknjaz and @bradmartin for support and tests.
 
+* Catch empty ssh-private-key input values and exit with a helpful
+  error message right away.
diff --git a/dist/index.js b/dist/index.js
index 602df64..5ee5d2f 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -58,9 +58,18 @@ const child_process = __webpack_require__(129);
 const fs = __webpack_require__(747);
 
 try {
+
     const home = process.env['HOME'];
     const homeSsh = home + '/.ssh';
 
+    const privateKey = core.getInput('ssh-private-key').trim();
+
+    if (!privateKey) {
+        core.setFailed("The ssh-private-key argument is empty. Maybe the secret has not been configured, or you are using a wrong secret name in your workflow file.");
+
+        return;
+    }
+
     console.log(`Adding GitHub.com keys to ${homeSsh}/known_hosts`);
     fs.mkdirSync(homeSsh, { recursive: true});
     fs.appendFileSync(`${homeSsh}/known_hosts`, '\ngithub.com ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAq2A7hRGmdnm9tUDbO9IDSwBK6TbQa+PXYPCPy6rbTrTtw7PHkccKrpp0yVhp5HdEIcKr6pLlVDBfOLX9QUsyCOV0wzfjIJNlGEYsdlLJizHhbn2mUjvSAHQqZETYP81eFzLQNnPHt4EVVUh7VfDESU84KezmD5QlWpXLmvU31/yMf+Se8xhHTvKSCZIFImWwoG6mbUoWf9nzpIoaSjB+weqqUUmpaaasXVal72J+UX2B+2RPW3RcT0eOzQgqlJL3RKrTJvdsjE3JEAvGq3lGHSZXy28G3skua2SmVi/w4yCE6gbODqnTWlg7+wC604ydGXA8VJiS5ap43JXiUFFAaQ==\n');
@@ -72,11 +81,13 @@ try {
     core.exportVariable('SSH_AUTH_SOCK', authSock);
 
     console.log("Adding private key to agent");
-    core.getInput('ssh-private-key').split(/(?=-----BEGIN)/).forEach(function(key) {
+    privateKey.split(/(?=-----BEGIN)/).forEach(function(key) {
         child_process.execSync('ssh-add -', { input: key.trim() + "\n" });
     });
+
     console.log("Keys added:");
     child_process.execSync('ssh-add -l', { stdio: 'inherit' });
+
 } catch (error) {
     core.setFailed(error.message);
 }
diff --git a/index.js b/index.js
index 140afb4..2da939f 100644
--- a/index.js
+++ b/index.js
@@ -3,9 +3,18 @@ const child_process = require('child_process');
 const fs = require('fs');
 
 try {
+
     const home = process.env['HOME'];
     const homeSsh = home + '/.ssh';
 
+    const privateKey = core.getInput('ssh-private-key').trim();
+
+    if (!privateKey) {
+        core.setFailed("The ssh-private-key argument is empty. Maybe the secret has not been configured, or you are using a wrong secret name in your workflow file.");
+
+        return;
+    }
+
     console.log(`Adding GitHub.com keys to ${homeSsh}/known_hosts`);
     fs.mkdirSync(homeSsh, { recursive: true});
     fs.appendFileSync(`${homeSsh}/known_hosts`, '\ngithub.com ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAq2A7hRGmdnm9tUDbO9IDSwBK6TbQa+PXYPCPy6rbTrTtw7PHkccKrpp0yVhp5HdEIcKr6pLlVDBfOLX9QUsyCOV0wzfjIJNlGEYsdlLJizHhbn2mUjvSAHQqZETYP81eFzLQNnPHt4EVVUh7VfDESU84KezmD5QlWpXLmvU31/yMf+Se8xhHTvKSCZIFImWwoG6mbUoWf9nzpIoaSjB+weqqUUmpaaasXVal72J+UX2B+2RPW3RcT0eOzQgqlJL3RKrTJvdsjE3JEAvGq3lGHSZXy28G3skua2SmVi/w4yCE6gbODqnTWlg7+wC604ydGXA8VJiS5ap43JXiUFFAaQ==\n');
@@ -17,11 +26,13 @@ try {
     core.exportVariable('SSH_AUTH_SOCK', authSock);
 
     console.log("Adding private key to agent");
-    core.getInput('ssh-private-key').split(/(?=-----BEGIN)/).forEach(function(key) {
+    privateKey.split(/(?=-----BEGIN)/).forEach(function(key) {
         child_process.execSync('ssh-add -', { input: key.trim() + "\n" });
     });
+
     console.log("Keys added:");
     child_process.execSync('ssh-add -l', { stdio: 'inherit' });
+
 } catch (error) {
     core.setFailed(error.message);
 }