diff --git a/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl.qll b/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl.qll
+++ b/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl2.qll b/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl2.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl2.qll
+++ b/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl2.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl3.qll b/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl3.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl3.qll
+++ b/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl3.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl4.qll b/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl4.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl4.qll
+++ b/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImpl4.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImplCommon.qll b/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImplCommon.qll
index 40a3dee078c..1319f972037 100644
--- a/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImplCommon.qll
+++ b/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImplCommon.qll
@@ -755,7 +755,7 @@ pragma[inline]
 DataFlowCallable getNodeEnclosingCallable(Node n) {
   exists(Node n0 |
     pragma[only_bind_into](n0) = n and
-    result = n0.getEnclosingCallable()
+    pragma[only_bind_into](result) = n0.getEnclosingCallable()
   )
 }
 
diff --git a/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImplLocal.qll b/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImplLocal.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImplLocal.qll
+++ b/cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowImplLocal.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl.qll b/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl.qll
+++ b/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl2.qll b/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl2.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl2.qll
+++ b/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl2.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl3.qll b/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl3.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl3.qll
+++ b/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl3.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl4.qll b/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl4.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl4.qll
+++ b/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl4.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImplCommon.qll b/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImplCommon.qll
index 40a3dee078c..1319f972037 100644
--- a/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImplCommon.qll
+++ b/cpp/ql/src/semmle/code/cpp/ir/dataflow/internal/DataFlowImplCommon.qll
@@ -755,7 +755,7 @@ pragma[inline]
 DataFlowCallable getNodeEnclosingCallable(Node n) {
   exists(Node n0 |
     pragma[only_bind_into](n0) = n and
-    result = n0.getEnclosingCallable()
+    pragma[only_bind_into](result) = n0.getEnclosingCallable()
   )
 }
 
diff --git a/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl.qll b/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl.qll
+++ b/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl2.qll b/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl2.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl2.qll
+++ b/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl2.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl3.qll b/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl3.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl3.qll
+++ b/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl3.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl4.qll b/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl4.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl4.qll
+++ b/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl4.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl5.qll b/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl5.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl5.qll
+++ b/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImpl5.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImplCommon.qll b/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImplCommon.qll
index 40a3dee078c..1319f972037 100644
--- a/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImplCommon.qll
+++ b/csharp/ql/src/semmle/code/csharp/dataflow/internal/DataFlowImplCommon.qll
@@ -755,7 +755,7 @@ pragma[inline]
 DataFlowCallable getNodeEnclosingCallable(Node n) {
   exists(Node n0 |
     pragma[only_bind_into](n0) = n and
-    result = n0.getEnclosingCallable()
+    pragma[only_bind_into](result) = n0.getEnclosingCallable()
   )
 }
 
diff --git a/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl.qll b/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl.qll
+++ b/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl2.qll b/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl2.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl2.qll
+++ b/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl2.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl3.qll b/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl3.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl3.qll
+++ b/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl3.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl4.qll b/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl4.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl4.qll
+++ b/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl4.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl5.qll b/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl5.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl5.qll
+++ b/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl5.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImplCommon.qll b/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImplCommon.qll
index 40a3dee078c..1319f972037 100644
--- a/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImplCommon.qll
+++ b/java/ql/src/semmle/code/java/dataflow/internal/DataFlowImplCommon.qll
@@ -755,7 +755,7 @@ pragma[inline]
 DataFlowCallable getNodeEnclosingCallable(Node n) {
   exists(Node n0 |
     pragma[only_bind_into](n0) = n and
-    result = n0.getEnclosingCallable()
+    pragma[only_bind_into](result) = n0.getEnclosingCallable()
   )
 }
 
diff --git a/python/ql/src/semmle/python/dataflow/new/internal/DataFlowImpl.qll b/python/ql/src/semmle/python/dataflow/new/internal/DataFlowImpl.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/python/ql/src/semmle/python/dataflow/new/internal/DataFlowImpl.qll
+++ b/python/ql/src/semmle/python/dataflow/new/internal/DataFlowImpl.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/python/ql/src/semmle/python/dataflow/new/internal/DataFlowImpl2.qll b/python/ql/src/semmle/python/dataflow/new/internal/DataFlowImpl2.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/python/ql/src/semmle/python/dataflow/new/internal/DataFlowImpl2.qll
+++ b/python/ql/src/semmle/python/dataflow/new/internal/DataFlowImpl2.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/python/ql/src/semmle/python/dataflow/new/internal/DataFlowImpl3.qll b/python/ql/src/semmle/python/dataflow/new/internal/DataFlowImpl3.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/python/ql/src/semmle/python/dataflow/new/internal/DataFlowImpl3.qll
+++ b/python/ql/src/semmle/python/dataflow/new/internal/DataFlowImpl3.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/python/ql/src/semmle/python/dataflow/new/internal/DataFlowImpl4.qll b/python/ql/src/semmle/python/dataflow/new/internal/DataFlowImpl4.qll
index 7b8ec090408..7fc9f8d6e00 100644
--- a/python/ql/src/semmle/python/dataflow/new/internal/DataFlowImpl4.qll
+++ b/python/ql/src/semmle/python/dataflow/new/internal/DataFlowImpl4.qll
@@ -765,7 +765,7 @@ private module Stage2 {
   bindingset[result, ap]
   private ApApprox getApprox(Ap ap) { any() }
 
-  private Ap getApNil(Node node) { PrevStage::revFlow(node, _) and result instanceof ApNil }
+  private ApNil getApNil(Node node) { PrevStage::revFlow(node, _) and exists(result) }
 
   bindingset[tc, tail]
   private Ap apCons(TypedContent tc, Ap tail) { result = true and exists(tc) and exists(tail) }
diff --git a/python/ql/src/semmle/python/dataflow/new/internal/DataFlowImplCommon.qll b/python/ql/src/semmle/python/dataflow/new/internal/DataFlowImplCommon.qll
index 40a3dee078c..1319f972037 100644
--- a/python/ql/src/semmle/python/dataflow/new/internal/DataFlowImplCommon.qll
+++ b/python/ql/src/semmle/python/dataflow/new/internal/DataFlowImplCommon.qll
@@ -755,7 +755,7 @@ pragma[inline]
 DataFlowCallable getNodeEnclosingCallable(Node n) {
   exists(Node n0 |
     pragma[only_bind_into](n0) = n and
-    result = n0.getEnclosingCallable()
+    pragma[only_bind_into](result) = n0.getEnclosingCallable()
   )
 }