diff --git a/llvm/lib/Target/RISCV/RISCVInstrFormats.td b/llvm/lib/Target/RISCV/RISCVInstrFormats.td
index b6b64b57b1b3e..e23001a3a0bff 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrFormats.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrFormats.td
@@ -193,7 +193,9 @@ class RVInstCommon<dag outs, dag ins, string opcodestr, string argstr,
   let AsmString = opcodestr # !if(!empty(argstr), "", "\t" # argstr);
   let Pattern = pattern;
 
-  let TSFlags{4-0} = format.Value;
+  InstFormat Format = format;
+
+  let TSFlags{4-0} = Format.Value;
 
   // Defaults
   RISCVVConstraint RVVConstraint = NoConstraint;
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfoZicbo.td b/llvm/lib/Target/RISCV/RISCVInstrInfoZicbo.td
index 878b85b141578..0723b2f568a79 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfoZicbo.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfoZicbo.td
@@ -41,6 +41,7 @@ class Prefetch_ri<bits<5> optype, string opcodestr>
               opcodestr, "${imm12}(${rs1})"> {
   let Inst{11-7} = 0b00000;
   let rs2 = optype;
+  let Format = InstFormatOther; // this does not follow the normal S format.
 }
 
 //===----------------------------------------------------------------------===//