diff --git a/rvfi/insns/insn_rem.py b/rvfi/insns/insn_rem.py
new file mode 100644
index 0000000..326627b
--- /dev/null
+++ b/rvfi/insns/insn_rem.py
@@ -0,0 +1,18 @@
+from .insn_rv32m_r_type import *
+
+"""
+REM instruction
+"""
+
+class InsnRem(InsnRV32MRType):
+    def __init__(self, params):
+        super().__init__(params, 0b110)
+    def elaborate(self, platform):
+        m = super().elaborate(platform)
+
+        if self.params.altops:
+            m.d.comb += self.spec_rd_wdata.eq(Mux(self.spec_rd_addr, (self.rvfi_rs1_rdata - self.rvfi_rs2_rdata) ^ 0xf5b7d8538da68fa5, 0))
+        else:
+            m.d.comb += self.spec_rd_wdata.eq(Mux(self.spec_rd_addr, Mux(self.rvfi_rs2_rdata == 0, self.rvfi_rs1_rdata, Mux((self.rvfi_rs1_rdata == (1 << (self.params.xlen - 1))) & (self.rvfi_rs2_rdata == 2 ** self.params.xlen - 1), 0, Value.as_signed(self.rvfi_rs1_rdata) % Value.as_signed(self.rvfi_rs2_rdata))), 0))
+
+        return m