diff --git a/sys/cddl/dev/dtrace/riscv/dtrace_subr.c b/sys/cddl/dev/dtrace/riscv/dtrace_subr.c
--- a/sys/cddl/dev/dtrace/riscv/dtrace_subr.c
+++ b/sys/cddl/dev/dtrace/riscv/dtrace_subr.c
@@ -272,6 +272,9 @@
 	if (invop == 0)
 		return (-1);
 
+	if (invop == DTRACE_INVOP_NOP)
+		return (0);
+
 	if (match_opcode(invop, (MATCH_SD | RS2_RA | RS1_SP),
 	    (MASK_SD | RS2_MASK | RS1_MASK))) {
 		/* Non-compressed store of ra to sp */