diff --git a/riscv64/riscv64asm/testdata/gnucases.txt b/riscv64/riscv64asm/testdata/gnucases.txt
index db1fc8f4..997591a8 100644
--- a/riscv64/riscv64asm/testdata/gnucases.txt
+++ b/riscv64/riscv64asm/testdata/gnucases.txt
@@ -410,6 +410,11 @@ a260|	ld x1,8(x2)
 8624|	fld f9,64(x2)
 3eb0|	fsd f15,32(x2)
 
+# 8.1. "Zicntr" Extension for Base Counters and Timers
+f32200c0|	rdcycle x5
+f32210c0|	rdtime x5
+f32220c0|	rdinstret x5
+
 # 10.1: "Zihintpause" Extension for Pause Hint, Version 1.0.0
 0f000001|	pause
 
diff --git a/riscv64/riscv64asm/testdata/plan9cases.txt b/riscv64/riscv64asm/testdata/plan9cases.txt
index a361d65e..ec90b79b 100644
--- a/riscv64/riscv64asm/testdata/plan9cases.txt
+++ b/riscv64/riscv64asm/testdata/plan9cases.txt
@@ -363,6 +363,11 @@ b35cbd49|	BEXT X27, X26, X25
 b3115228|	BSET X5, X4, X3
 1393f32b|	BSETI $63, X7, X6
 
+# 8.1. "Zicntr" Extension for Base Counters and Timers
+f32200c0|	RDCYCLE X5
+f32210c0|	RDTIME X5
+f32220c0|	RDINSTRET X5
+
 # 10.1: "Zihintpause" Extension for Pause Hint, Version 1.0.0
 0f000001|	PAUSE