diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index 92d2516bc0..452422d03e 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,8 @@
+2016-12-20  Andrew Waterman  <andrew@sifive.com>
+
+	* riscv-opc.c (riscv_opcodes): Change jr and jalr to "o(s)"
+	format.
+
 2016-12-20  Andrew Waterman  <andrew@sifive.com>
 
 	* riscv-dis.c (riscv_disassemble_insn): Default to the ELF's
diff --git a/opcodes/riscv-opc.c b/opcodes/riscv-opc.c
index 256e089c63..69fca09ace 100644
--- a/opcodes/riscv-opc.c
+++ b/opcodes/riscv-opc.c
@@ -132,11 +132,14 @@ const struct riscv_opcode riscv_opcodes[] =
 {"ret",       "I",   "",  MATCH_JALR | (X_RA << OP_SH_RS1), MASK_JALR | MASK_RD | MASK_RS1 | MASK_IMM, match_opcode, INSN_ALIAS },
 {"jr",        "C",   "d",  MATCH_C_JR, MASK_C_JR, match_rd_nonzero, INSN_ALIAS },
 {"jr",        "I",   "s",  MATCH_JALR, MASK_JALR | MASK_RD | MASK_IMM, match_opcode, INSN_ALIAS },
+{"jr",        "I",   "o(s)",  MATCH_JALR, MASK_JALR | MASK_RD, match_opcode, INSN_ALIAS },
 {"jr",        "I",   "s,j",  MATCH_JALR, MASK_JALR | MASK_RD, match_opcode, INSN_ALIAS },
 {"jalr",      "C",   "d",  MATCH_C_JALR, MASK_C_JALR, match_rd_nonzero, INSN_ALIAS },
 {"jalr",      "I",   "s",  MATCH_JALR | (X_RA << OP_SH_RD), MASK_JALR | MASK_RD | MASK_IMM, match_opcode, INSN_ALIAS },
+{"jalr",      "I",   "o(s)",  MATCH_JALR | (X_RA << OP_SH_RD), MASK_JALR | MASK_RD, match_opcode, INSN_ALIAS },
 {"jalr",      "I",   "s,j",  MATCH_JALR | (X_RA << OP_SH_RD), MASK_JALR | MASK_RD, match_opcode, INSN_ALIAS },
 {"jalr",      "I",   "d,s",  MATCH_JALR, MASK_JALR | MASK_IMM, match_opcode, INSN_ALIAS },
+{"jalr",      "I",   "d,o(s)",  MATCH_JALR, MASK_JALR, match_opcode, 0 },
 {"jalr",      "I",   "d,s,j",  MATCH_JALR, MASK_JALR, match_opcode, 0 },
 {"j",         "C",   "Ca",  MATCH_C_J, MASK_C_J, match_opcode, INSN_ALIAS },
 {"j",         "I",   "a",  MATCH_JAL, MASK_JAL | MASK_RD, match_opcode, INSN_ALIAS },