diff --git a/spring-cloud-function-deployer/src/main/java/org/springframework/cloud/function/deployer/FunctionArchiveDeployer.java b/spring-cloud-function-deployer/src/main/java/org/springframework/cloud/function/deployer/FunctionArchiveDeployer.java
index 635a48bc2..88519a9fb 100644
--- a/spring-cloud-function-deployer/src/main/java/org/springframework/cloud/function/deployer/FunctionArchiveDeployer.java
+++ b/spring-cloud-function-deployer/src/main/java/org/springframework/cloud/function/deployer/FunctionArchiveDeployer.java
@@ -187,6 +187,9 @@ class FunctionArchiveDeployer extends JarLauncher {
 
 	private boolean isBootApplicationWithMain() {
 		try {
+			if (this.getArchive().getManifest() == null) {
+				return false;
+			}
 			return StringUtils.hasText(this.getArchive().getManifest().getMainAttributes().getValue("Start-Class"));
 		}
 		catch (Exception e) {
diff --git a/spring-cloud-function-deployer/src/main/java/org/springframework/cloud/function/deployer/FunctionDeployerConfiguration.java b/spring-cloud-function-deployer/src/main/java/org/springframework/cloud/function/deployer/FunctionDeployerConfiguration.java
index 7f68381af..4634851c7 100644
--- a/spring-cloud-function-deployer/src/main/java/org/springframework/cloud/function/deployer/FunctionDeployerConfiguration.java
+++ b/spring-cloud-function-deployer/src/main/java/org/springframework/cloud/function/deployer/FunctionDeployerConfiguration.java
@@ -46,6 +46,7 @@ import org.springframework.core.env.ConfigurableEnvironment;
  * and {@link SmartLifecycle#stop()} operations.
  * <br>
  * @author Oleg Zhurakousky
+ * @author Eric Bottard
  *
  * @since 3.0
  *
diff --git a/spring-cloud-function-deployer/src/test/java/org/springframework/cloud/function/deployer/FunctionDeployerTests.java b/spring-cloud-function-deployer/src/test/java/org/springframework/cloud/function/deployer/FunctionDeployerTests.java
index 2c6c81abd..c7d764498 100644
--- a/spring-cloud-function-deployer/src/test/java/org/springframework/cloud/function/deployer/FunctionDeployerTests.java
+++ b/spring-cloud-function-deployer/src/test/java/org/springframework/cloud/function/deployer/FunctionDeployerTests.java
@@ -86,6 +86,26 @@ public class FunctionDeployerTests {
 		assertThat(results.get(1)).isEqualTo("STACY");
 	}
 
+	@Test
+	public void testWithSimplestJarExploaded() throws Exception {
+		String[] args = new String[] {
+				"--spring.cloud.function.location=target/it/simplestjar/target/classes",
+				"--spring.cloud.function.function-class=function.example.UpperCaseFunction" };
+
+		ApplicationContext context = SpringApplication.run(DeployerApplication.class, args);
+		FunctionCatalog catalog = context.getBean(FunctionCatalog.class);
+		Function<String, String> function = catalog.lookup("upperCaseFunction");
+
+		assertThat(function.apply("bob")).isEqualTo("BOB");
+		assertThat(function.apply("stacy")).isEqualTo("STACY");
+
+		Function<Flux<String>, Flux<String>> functionAsFlux = catalog.lookup("upperCaseFunction");
+
+		List<String> results = functionAsFlux.apply(Flux.just("bob", "stacy")).collectList().block();
+		assertThat(results.get(0)).isEqualTo("BOB");
+		assertThat(results.get(1)).isEqualTo("STACY");
+	}
+
 	/*
 	 * Target function `class UpperCaseFunction implements Function<String, String>`
 	 * No Main/Start class present, no Spring configuration