diff --git a/polly/include/polly/CodeGen/IslAst.h b/polly/include/polly/CodeGen/IslAst.h
--- a/polly/include/polly/CodeGen/IslAst.h
+++ b/polly/include/polly/CodeGen/IslAst.h
@@ -139,7 +139,7 @@
   static IslAstUserPayload *getNodePayload(const isl::ast_node &Node);
 
   /// Is this loop an innermost loop?
-  static bool isInnermost(__isl_keep isl_ast_node *Node);
+  static bool isInnermost(const isl::ast_node &Node);
 
   /// Is this loop a parallel loop?
   static bool isParallel(__isl_keep isl_ast_node *Node);
diff --git a/polly/lib/CodeGen/IslAst.cpp b/polly/lib/CodeGen/IslAst.cpp
--- a/polly/lib/CodeGen/IslAst.cpp
+++ b/polly/lib/CodeGen/IslAst.cpp
@@ -588,8 +588,8 @@
   return Payload;
 }
 
-bool IslAstInfo::isInnermost(__isl_keep isl_ast_node *Node) {
-  IslAstUserPayload *Payload = getNodePayload(isl::manage_copy(Node));
+bool IslAstInfo::isInnermost(const isl::ast_node &Node) {
+  IslAstUserPayload *Payload = getNodePayload(Node);
   return Payload && Payload->IsInnermost;
 }
 
@@ -626,7 +626,7 @@
   //       executed. This can possibly require run-time checks, which again
   //       raises the question of both run-time check overhead and code size
   //       costs.
-  if (!PollyParallelForce && isInnermost(Node))
+  if (!PollyParallelForce && isInnermost(isl::manage_copy(Node)))
     return false;
 
   return isOutermostParallel(isl::manage_copy(Node)) &&