diff --git a/compiler/GHC/Platform/Reg/Class.hs b/compiler/GHC/Platform/Reg/Class.hs
index e76f8af036aa4aa6c522e0c2221acfbdb13dd5f0..23b3c24b2a5db501af57730b921e6c90f1d55a09 100644
--- a/compiler/GHC/Platform/Reg/Class.hs
+++ b/compiler/GHC/Platform/Reg/Class.hs
@@ -49,5 +49,8 @@ registerArch arch =
     ArchPPC       -> Unified
     ArchPPC_64 {} -> Unified
     ArchAArch64   -> Unified
-    ArchRISCV64   -> Separate
+    -- Support for vector registers not yet implemented for RISC-V
+    -- see panic in `getFreeRegs`.
+    --ArchRISCV64   -> Separate
+    ArchRISCV64   -> NoVectors
     _             -> NoVectors