diff --git a/runtime/benchmark/src/main/java/mb/spoofax/runtime/benchmark/state/ObservingExecState.java b/runtime/benchmark/src/main/java/mb/spoofax/runtime/benchmark/state/ObservingExecState.java
index 2b2c0d87a..4b239c85f 100644
--- a/runtime/benchmark/src/main/java/mb/spoofax/runtime/benchmark/state/ObservingExecState.java
+++ b/runtime/benchmark/src/main/java/mb/spoofax/runtime/benchmark/state/ObservingExecState.java
@@ -3,6 +3,7 @@
 import kotlin.Unit;
 import mb.pie.runtime.core.ExecException;
 import mb.pie.runtime.core.FuncApp;
+import mb.pie.runtime.core.exec.ExecutionVariant;
 import mb.pie.runtime.core.exec.ObservingExecutor;
 import mb.pie.runtime.core.impl.exec.ObservingExecutorImpl;
 import mb.spoofax.runtime.pie.builder.SpoofaxPipeline;
@@ -40,7 +41,8 @@ public void exec(WorkspaceState workspaceState, List<PPath> changedPaths) {
 
     private void init(SpoofaxPieState spoofaxPieState, WorkspaceState workspaceState, InfraState infraState) {
         this.executor =
-            new ObservingExecutorImpl(infraState.store, infraState.cache, infraState.share, infraState.layer,
+            new ObservingExecutorImpl(infraState.store, infraState.cache, ExecutionVariant.Naive, infraState.share,
+                infraState.layer,
                 infraState.logger, spoofaxPieState.logger, infraState.funcs);
         final PPath root = workspaceState.root;
         try(final Stream<PPath> stream = root.list(PPaths.directoryPathMatcher())) {
diff --git a/runtime/eclipse/src/main/java/mb/spoofax/runtime/eclipse/pipeline/ObservingPipelineAdapter.java b/runtime/eclipse/src/main/java/mb/spoofax/runtime/eclipse/pipeline/ObservingPipelineAdapter.java
index 00844bb2f..2ae2570d4 100644
--- a/runtime/eclipse/src/main/java/mb/spoofax/runtime/eclipse/pipeline/ObservingPipelineAdapter.java
+++ b/runtime/eclipse/src/main/java/mb/spoofax/runtime/eclipse/pipeline/ObservingPipelineAdapter.java
@@ -19,6 +19,7 @@
 import mb.log.Logger;
 import mb.pie.runtime.core.ExecException;
 import mb.pie.runtime.core.FuncApp;
+import mb.pie.runtime.core.exec.ExecutionVariant;
 import mb.pie.runtime.core.exec.ObservingExecutor;
 import mb.spoofax.runtime.eclipse.SpoofaxPlugin;
 import mb.spoofax.runtime.eclipse.editor.SpoofaxEditor;
@@ -58,7 +59,7 @@ public class ObservingPipelineAdapter implements PipelineAdapter {
         this.eclipseRoot = ResourcesPlugin.getWorkspace().getRoot();
         this.root = pathSrv.resolve(eclipseRoot);
 
-        this.executor = pieSrv.getObservingExecutor(root, SpoofaxPlugin.useInMemoryStore);
+        this.executor = pieSrv.getObservingExecutor(root, SpoofaxPlugin.useInMemoryStore, ExecutionVariant.DirtyFlagging);
     }
 
 
diff --git a/runtime/pie/src/main/kotlin/mb/spoofax/runtime/pie/Service.kt b/runtime/pie/src/main/kotlin/mb/spoofax/runtime/pie/Service.kt
index 624daead3..2f582ef0b 100644
--- a/runtime/pie/src/main/kotlin/mb/spoofax/runtime/pie/Service.kt
+++ b/runtime/pie/src/main/kotlin/mb/spoofax/runtime/pie/Service.kt
@@ -15,7 +15,7 @@ import java.util.concurrent.ConcurrentHashMap
 interface PieSrv {
   fun getPullingExecutor(dir: PPath, useInMemoryStore: Boolean): PullingExecutor
   fun getDirtyFlaggingExecutor(dir: PPath, useInMemoryStore: Boolean): DirtyFlaggingExecutor
-  fun getObservingExecutor(dir: PPath, useInMemoryStore: Boolean): ObservingExecutor
+  fun getObservingExecutor(dir: PPath, useInMemoryStore: Boolean, executionVariant: ExecutionVariant = ExecutionVariant.Naive): ObservingExecutor
 }
 
 class PieSrvImpl @Inject constructor(
@@ -49,11 +49,11 @@ class PieSrvImpl @Inject constructor(
     }
   }
 
-  override fun getObservingExecutor(dir: PPath, useInMemoryStore: Boolean): ObservingExecutor {
+  override fun getObservingExecutor(dir: PPath, useInMemoryStore: Boolean, executionVariant: ExecutionVariant): ObservingExecutor {
     return observingExecutors.getOrPut(dir) {
       val store = getStore(dir, useInMemoryStore)
       val cache = getCache(dir)
-      observingExecutorFactory.create(store, cache)
+      observingExecutorFactory.create(store, cache, executionVariant)
     }
   }