diff --git a/src/hotspot/share/opto/parse1.cpp b/src/hotspot/share/opto/parse1.cpp
index 414a1f3c00e..d103f58e03a 100644
--- a/src/hotspot/share/opto/parse1.cpp
+++ b/src/hotspot/share/opto/parse1.cpp
@@ -1048,6 +1048,15 @@ void Parse::do_exits() {
       // loading.  It could also be due to an error, so mark this method as not compilable because
       // otherwise this could lead to an infinite compile loop.
       // In any case, this code path is rarely (and never in my testing) reached.
+#ifdef ASSERT
+      tty->print_cr("# Can't determine return type.");
+      tty->print_cr("# exit control");
+      _exits.control()->dump(2);
+      tty->print_cr("# ret phi type");
+      _gvn.type(ret_phi)->dump();
+      tty->print_cr("# ret phi");
+      ret_phi->dump(2);
+#endif // ASSERT
       assert(false, "Can't determine return type.");
       C->record_method_not_compilable("Can't determine return type.");
       return;