diff --git a/spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/resource/ResourceController.java b/spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/resource/ResourceController.java
index d228bf44..467f2d26 100644
--- a/spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/resource/ResourceController.java
+++ b/spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/resource/ResourceController.java
@@ -145,14 +145,16 @@ public class ResourceController {
 		// ensure InputStream will be closed to prevent file locks on Windows
 		try (InputStream is = resource.getInputStream()) {
 			String text = StreamUtils.copyToString(is, Charset.forName("UTF-8"));
-			String ext = StringUtils.getFilenameExtension(resource.getFilename())
-					.toLowerCase();
+			String ext = StringUtils.getFilenameExtension(resource.getFilename());
+			if (ext != null) {
+				ext = ext.toLowerCase();
+			}
 			Environment environment = this.environmentRepository.findOne(name, profile,
 					label, false);
 			if (resolvePlaceholders) {
 				text = resolvePlaceholders(prepareEnvironment(environment), text);
 			}
-			if (encryptEnabled && plainTextEncryptEnabled) {
+			if (ext != null && encryptEnabled && plainTextEncryptEnabled) {
 				ResourceEncryptor re = this.resourceEncryptorMap.get(ext);
 				if (re == null) {
 					logger.warn("Cannot decrypt for extension " + ext);
diff --git a/spring-cloud-config-server/src/test/java/org/springframework/cloud/config/server/resource/ResourceControllerTests.java b/spring-cloud-config-server/src/test/java/org/springframework/cloud/config/server/resource/ResourceControllerTests.java
index acd08695..00565416 100644
--- a/spring-cloud-config-server/src/test/java/org/springframework/cloud/config/server/resource/ResourceControllerTests.java
+++ b/spring-cloud-config-server/src/test/java/org/springframework/cloud/config/server/resource/ResourceControllerTests.java
@@ -175,6 +175,13 @@ public class ResourceControllerTests {
 		assertThat(resource).isEqualToIgnoringNewLines("foo: dev_bar/spam");
 	}
 
+	@Test
+	public void resourceWithoutFileExtension() throws Exception {
+		this.environmentRepository.setSearchLocations("classpath:/test");
+		String resource = this.controller.retrieve("foo", "bar", "dev", "foo", true);
+		assertThat(resource).isEqualToIgnoringNewLines("foo: dev_bar");
+	}
+
 	@Test
 	public void resourceWithSlash() throws Exception {
 		this.environmentRepository.setSearchLocations("classpath:/test");
diff --git a/spring-cloud-config-server/src/test/resources/test/dev/foo b/spring-cloud-config-server/src/test/resources/test/dev/foo
new file mode 100644
index 00000000..be18679f
--- /dev/null
+++ b/spring-cloud-config-server/src/test/resources/test/dev/foo
@@ -0,0 +1 @@
+foo: dev_bar