diff --git a/src/coreclr/tools/Common/InstructionSetHelpers.cs b/src/coreclr/tools/Common/InstructionSetHelpers.cs
index f25320e99f785d..ed7f1649449091 100644
--- a/src/coreclr/tools/Common/InstructionSetHelpers.cs
+++ b/src/coreclr/tools/Common/InstructionSetHelpers.cs
@@ -299,7 +299,8 @@ public static InstructionSetSupport ConfigureInstructionSetSupport(string instru
                 optimisticInstructionSetSupportBuilder.AddSupportedInstructionSet("dotprod");
                 optimisticInstructionSetSupportBuilder.AddSupportedInstructionSet("lse");
                 optimisticInstructionSetSupportBuilder.AddSupportedInstructionSet("rcpc");
-                optimisticInstructionSetSupportBuilder.AddSupportedInstructionSet("rcpc2");
+                // RCPC2 is intentionally excluded from the optimistic set since it is not universally available
+                // on supported ARM64 hardware yet, and many methods take an opportunistic dependency on it.
                 optimisticInstructionSetSupportBuilder.AddSupportedInstructionSet("rdma");
                 optimisticInstructionSetSupportBuilder.AddSupportedInstructionSet("sha1");
                 optimisticInstructionSetSupportBuilder.AddSupportedInstructionSet("sha2");