diff --git a/vscode-extensions/vscode-concourse/src/main/java/org/springframework/ide/vscode/concourse/PipelineYmlSchema.java b/vscode-extensions/vscode-concourse/src/main/java/org/springframework/ide/vscode/concourse/PipelineYmlSchema.java
index 064e1fcab..108bfe74b 100644
--- a/vscode-extensions/vscode-concourse/src/main/java/org/springframework/ide/vscode/concourse/PipelineYmlSchema.java
+++ b/vscode-extensions/vscode-concourse/src/main/java/org/springframework/ide/vscode/concourse/PipelineYmlSchema.java
@@ -194,6 +194,7 @@ public class PipelineYmlSchema implements YamlSchema {
 		addProp(task, "outputs", f.yseq(t_output));
 		addProp(task, "run", t_command).isRequired(true);
 		addProp(task, "params", t_string_params);
+		task.requireOneOf("image_resource", "image");
 
 		YBeanType getStep = f.ybean("GetStep");
 		addProp(getStep, "get", t_resource_name);
diff --git a/vscode-extensions/vscode-concourse/src/test/java/org/springframework/ide/vscode/concourse/ConcourseEditorTest.java b/vscode-extensions/vscode-concourse/src/test/java/org/springframework/ide/vscode/concourse/ConcourseEditorTest.java
index 4554beddc..42e140bcd 100644
--- a/vscode-extensions/vscode-concourse/src/test/java/org/springframework/ide/vscode/concourse/ConcourseEditorTest.java
+++ b/vscode-extensions/vscode-concourse/src/test/java/org/springframework/ide/vscode/concourse/ConcourseEditorTest.java
@@ -1675,8 +1675,10 @@ public class ConcourseEditorTest {
 				"params: the-params\n"
 		);
 		editor.assertProblems(
+				"image_resource|Only one of [image_resource, image] should be defined",
 				"name|Unknown property",
 				"bogus-source-prop|Unknown property",
+				"image|Only one of [image_resource, image] should be defined",
 				"path: path/to/input|'name' is required",
 				"path: path/to/output|'name' is required",
 				"the-params|Expecting a 'Map'"
@@ -1768,8 +1770,10 @@ public class ConcourseEditorTest {
 				"      params: the-params"
 		);
 		editor.assertProblems(
+				"image_resource|Only one of [image_resource, image] should be defined",
 				"name|Unknown property",
 				"bogus-source-prop|Unknown property",
+				"image|Only one of [image_resource, image] should be defined",
 				"path: path/to/input|'name' is required",
 				"path: path/to/output|'name' is required",
 				"the-params|Expecting a 'Map'"