1 files changed, 4 insertions, 3 deletions
diff --git a/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/BuildCommand.java b/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/BuildCommand.java
index 1ab24b9c6..49962eadb 100644
--- a/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/BuildCommand.java
+++ b/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/BuildCommand.java
@@ -149,14 +149,15 @@ public class BuildCommand extends ModelObject implements ICommand {
 	}
 
 	/**
-	 * @return Map {@link IBuildConfiguration} -> {@link IncrementalProjectBuilder} if
+	 * @return A copy of the internal map {@link IBuildConfiguration} -> {@link IncrementalProjectBuilder} if
 	 * this build command supports multiple configurations. Otherwise return the {@link IncrementalProjectBuilder}
 	 * associated with this build command.
 	 */
 	public Object getBuilders() {
 		synchronized (builderLock) {
-			if (supportsConfigs())
-				return builders;
+			if (supportsConfigs()) {
+				return builders == null ? null : new HashMap<>(builders);
+			}
 			return builder;
 		}
 	}