diff --git a/c/cert/src/rules/EXP16-C/DoNotCompareFunctionPointersToConstantValues.ql b/c/cert/src/rules/EXP16-C/DoNotCompareFunctionPointersToConstantValues.ql
index 5f347d817..812d4d910 100644
--- a/c/cert/src/rules/EXP16-C/DoNotCompareFunctionPointersToConstantValues.ql
+++ b/c/cert/src/rules/EXP16-C/DoNotCompareFunctionPointersToConstantValues.ql
@@ -51,7 +51,7 @@ class ExplicitComparison extends EffectivelyComparison, FinalComparisonOperation
   override FunctionExpr getFunctionExpr() { result = funcExpr }
 }
 
-class ImplicitComparison extends EffectivelyComparison, GuardCondition {
+class ImplicitComparison extends EffectivelyComparison, GuardCondition instanceof Expr {
   ImplicitComparison() {
     this instanceof FunctionExpr and
     not getParent() instanceof ComparisonOperation
diff --git a/cpp/cert/src/rules/CTR55-CPP/DoNotUseAnAdditiveOperatorOnAnIterator.ql b/cpp/cert/src/rules/CTR55-CPP/DoNotUseAnAdditiveOperatorOnAnIterator.ql
index c6ea2c451..1fdbbcb84 100644
--- a/cpp/cert/src/rules/CTR55-CPP/DoNotUseAnAdditiveOperatorOnAnIterator.ql
+++ b/cpp/cert/src/rules/CTR55-CPP/DoNotUseAnAdditiveOperatorOnAnIterator.ql
@@ -78,8 +78,8 @@ predicate isUpperBoundEndCheckedIteratorAccess(IteratorSource source, ContainerI
     basicBlockOfIteratorAccess.contains(it) and
     //guard is comprised of end check and an iterator access
     DataFlow::localFlow(DataFlow::exprNode(referenceToOnePassedTheEndElement),
-      DataFlow::exprNode(upperBoundCheck.getChild(_))) and
-    upperBoundCheck.getChild(_) = checkedIteratorAccess and
+      DataFlow::exprNode(upperBoundCheck.(Expr).getChild(_))) and
+    upperBoundCheck.(Expr).getChild(_) = checkedIteratorAccess and
     //make sure its the same iterator being checked in the guard as accessed
     checkedIteratorAccess.getOwningContainer() = it.getOwningContainer() and
     //if its the end call itself (or its parts), make sure its the same container providing its end as giving the iterator
diff --git a/cpp/cert/src/rules/MEM52-CPP/DetectAndHandleMemoryAllocationErrors.ql b/cpp/cert/src/rules/MEM52-CPP/DetectAndHandleMemoryAllocationErrors.ql
index 90685f1c9..ac9281ee9 100644
--- a/cpp/cert/src/rules/MEM52-CPP/DetectAndHandleMemoryAllocationErrors.ql
+++ b/cpp/cert/src/rules/MEM52-CPP/DetectAndHandleMemoryAllocationErrors.ql
@@ -63,7 +63,7 @@ class NoThrowAllocExprWrapperFunction extends Function {
     n.getEnclosingFunction() = this and
     DataFlow::localExprFlow(n, any(ReturnStmt rs).getExpr()) and
     // Not checked in this wrapper function
-    not exists(GuardCondition gc | DataFlow::localExprFlow(n, gc.getAChild*()))
+    not exists(GuardCondition gc | DataFlow::localExprFlow(n, gc.(Expr).getAChild*()))
   }
 
   /** Gets the underlying nothrow allocation ultimately being wrapped. */
diff --git a/cpp/common/src/codingstandards/cpp/rules/functionerroneousreturnvaluenottested/FunctionErroneousReturnValueNotTested.qll b/cpp/common/src/codingstandards/cpp/rules/functionerroneousreturnvaluenottested/FunctionErroneousReturnValueNotTested.qll
index e7e25cf7b..83907c609 100644
--- a/cpp/common/src/codingstandards/cpp/rules/functionerroneousreturnvaluenottested/FunctionErroneousReturnValueNotTested.qll
+++ b/cpp/common/src/codingstandards/cpp/rules/functionerroneousreturnvaluenottested/FunctionErroneousReturnValueNotTested.qll
@@ -56,7 +56,7 @@ query predicate problems(FunctionCall fc, string message) {
           "vsnwprintf_s"
         ]) and
   not exists(GuardCondition gc |
-    DataFlow::localFlow(DataFlow::exprNode(fc), DataFlow::exprNode(gc.getAChild*()))
+    DataFlow::localFlow(DataFlow::exprNode(fc), DataFlow::exprNode(gc.(Expr).getAChild*()))
   ) and
   message = "Return value from " + fc.getTarget().getName() + " is not tested for errors."
 }