diff --git a/core/src/main/java/io/kestra/core/secret/SecretService.java b/core/src/main/java/io/kestra/core/secret/SecretService.java
index 1adb420b02e..db5616b345d 100644
--- a/core/src/main/java/io/kestra/core/secret/SecretService.java
+++ b/core/src/main/java/io/kestra/core/secret/SecretService.java
@@ -38,6 +38,10 @@ public void decode() {
     }
 
     public String findSecret(String tenantId, String namespace, String key) throws SecretNotFoundException, IOException {
-        return decodedSecrets.get(key.toUpperCase());
+        String secret = decodedSecrets.get(key.toUpperCase());
+        if (secret == null) {
+            throw new SecretNotFoundException("Cannot find secret for key '" + key + "'.");
+        }
+        return secret;
     }
 }
diff --git a/core/src/test/java/io/kestra/core/secret/SecretFunctionTest.java b/core/src/test/java/io/kestra/core/secret/SecretFunctionTest.java
index 00544b67607..505c162c17f 100644
--- a/core/src/test/java/io/kestra/core/secret/SecretFunctionTest.java
+++ b/core/src/test/java/io/kestra/core/secret/SecretFunctionTest.java
@@ -23,6 +23,7 @@
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.*;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 @KestraTest
 public class SecretFunctionTest extends AbstractMemoryRunnerTest {
@@ -53,9 +54,9 @@ void getSecret() throws TimeoutException, QueueException {
     }
 
     @Test
-    void getUnknownSecret() throws IllegalVariableEvaluationException, IOException {
-        String secret = secretService.findSecret(null, null, "unknown_secret_key");
+    void getUnknownSecret() {
+        var exception = assertThrows(SecretNotFoundException.class, () -> secretService.findSecret(null, null, "unknown_secret_key"));
 
-        assertThat(secret, nullValue());
+        assertThat(exception.getMessage(), is("Cannot find secret for key 'unknown_secret_key'."));
     }
 }