diff --git a/disasm/isa_parser.cc b/disasm/isa_parser.cc
index 69c3e34bc2..757007353f 100644
--- a/disasm/isa_parser.cc
+++ b/disasm/isa_parser.cc
@@ -344,6 +344,8 @@ isa_parser_t::isa_parser_t(const char* str, const char *priv)
       extension_table[EXT_SMNPM] = true;
     } else if (ext_str == "ssnpm") {
       extension_table[EXT_SSNPM] = true;
+    } else if (ext_str == "shlcofideleg") {
+      extension_table[EXT_SHLCOFIDELEG] = true;
     } else if (ext_str.substr(0, 3) == "zvl") {
       reg_t new_vlen;
       try {
diff --git a/riscv/csr_init.cc b/riscv/csr_init.cc
index a03d188d4c..a70830c478 100644
--- a/riscv/csr_init.cc
+++ b/riscv/csr_init.cc
@@ -109,11 +109,11 @@ void state_t::csr_init(processor_t* const proc, reg_t max_isa)
 
   auto vsip_vsie_accr = std::make_shared<generic_int_accessor_t>(
     this,
-    MIP_VS_MASK,   // read_mask
-    MIP_VSSIP,     // ip_write_mask
-    MIP_VS_MASK,   // ie_write_mask
+    MIP_VS_MASK | MIP_LCOFIP,   // read_mask
+    MIP_VSSIP,                  // ip_write_mask
+    MIP_VS_MASK | MIP_LCOFIP,   // ie_write_mask
     generic_int_accessor_t::mask_mode_t::HIDELEG,
-    1              // shiftamt
+    1                           // shiftamt
   );
 
   auto nonvirtual_sip = std::make_shared<mip_proxy_csr_t>(proc, CSR_SIP, sip_sie_accr);
diff --git a/riscv/csrs.cc b/riscv/csrs.cc
index ea535f6fe3..a8f89ce888 100644
--- a/riscv/csrs.cc
+++ b/riscv/csrs.cc
@@ -834,21 +834,23 @@ generic_int_accessor_t::generic_int_accessor_t(state_t* const state,
 }
 
 reg_t generic_int_accessor_t::ip_read() const noexcept {
-  return (state->mip->read() & deleg_mask() & read_mask) >> shiftamt;
+  const reg_t val = state->mip->read() & deleg_mask() & read_mask;
+  return ((val & 0xfff) >> shiftamt) | (val & ~0xfff);
 }
 
 void generic_int_accessor_t::ip_write(const reg_t val) noexcept {
   const reg_t mask = deleg_mask() & ip_write_mask;
-  state->mip->write_with_mask(mask, val << shiftamt);
+  state->mip->write_with_mask(mask, ((val & 0xfff) << shiftamt) | (val & ~0xfff));
 }
 
 reg_t generic_int_accessor_t::ie_read() const noexcept {
-  return (state->mie->read() & deleg_mask() & read_mask) >> shiftamt;
+  const reg_t val = state->mie->read() & deleg_mask() & read_mask;
+  return ((val & 0xfff) >> shiftamt) | (val & ~0xfff);
 }
 
 void generic_int_accessor_t::ie_write(const reg_t val) noexcept {
   const reg_t mask = deleg_mask() & ie_write_mask;
-  state->mie->write_with_mask(mask, val << shiftamt);
+  state->mie->write_with_mask(mask, ((val & 0xfff) << shiftamt) | (val & ~0xfff));
 }
 
 reg_t generic_int_accessor_t::deleg_mask() const {
@@ -1223,7 +1225,8 @@ void hypervisor_csr_t::verify_permissions(insn_t insn, bool write) const {
 }
 
 hideleg_csr_t::hideleg_csr_t(processor_t* const proc, const reg_t addr, csr_t_p mideleg):
-  masked_csr_t(proc, addr, MIP_VS_MASK, 0),
+  masked_csr_t(proc, addr, MIP_VS_MASK | 
+    (proc->extension_enabled(EXT_SHLCOFIDELEG) ? MIP_LCOFIP : 0), 0),
   mideleg(mideleg) {
 }
 
diff --git a/riscv/isa_parser.h b/riscv/isa_parser.h
index 90e1ec1650..fa9fb4e84e 100644
--- a/riscv/isa_parser.h
+++ b/riscv/isa_parser.h
@@ -86,6 +86,7 @@ typedef enum {
   EXT_SMMPM,
   EXT_SMNPM,
   EXT_SSNPM,
+  EXT_SHLCOFIDELEG,
   NUM_ISA_EXTENSIONS
 } isa_extension_t;