diff --git a/src/cmd/compile/internal/amd64/ssa.go b/src/cmd/compile/internal/amd64/ssa.go
index ca5f36e7759..7e2dc41928f 100644
--- a/src/cmd/compile/internal/amd64/ssa.go
+++ b/src/cmd/compile/internal/amd64/ssa.go
@@ -1005,14 +1005,18 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 	case ssa.OpAMD64CALLstatic:
 		if buildcfg.Experiment.RegabiG && s.ABI == obj.ABI0 && v.Aux.(*ssa.AuxCall).Fn.ABI() == obj.ABIInternal {
 			// zeroing X15 when entering ABIInternal from ABI0
-			opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
+			if buildcfg.GOOS != "plan9" { // do not use SSE on Plan 9
+				opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
+			}
 			// set G register from TLS
 			getgFromTLS(s, x86.REG_R14)
 		}
 		s.Call(v)
 		if buildcfg.Experiment.RegabiG && s.ABI == obj.ABIInternal && v.Aux.(*ssa.AuxCall).Fn.ABI() == obj.ABI0 {
 			// zeroing X15 when entering ABIInternal from ABI0
-			opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
+			if buildcfg.GOOS != "plan9" { // do not use SSE on Plan 9
+				opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
+			}
 			// set G register from TLS
 			getgFromTLS(s, x86.REG_R14)
 		}
@@ -1306,7 +1310,9 @@ func ssaGenBlock(s *ssagen.State, b, next *ssa.Block) {
 	case ssa.BlockRetJmp:
 		if buildcfg.Experiment.RegabiG && s.ABI == obj.ABI0 && b.Aux.(*obj.LSym).ABI() == obj.ABIInternal {
 			// zeroing X15 when entering ABIInternal from ABI0
-			opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
+			if buildcfg.GOOS != "plan9" { // do not use SSE on Plan 9
+				opregreg(s, x86.AXORPS, x86.REG_X15, x86.REG_X15)
+			}
 			// set G register from TLS
 			getgFromTLS(s, x86.REG_R14)
 		}
diff --git a/src/runtime/asm_amd64.s b/src/runtime/asm_amd64.s
index 14f29e19647..5990ce54c8d 100644
--- a/src/runtime/asm_amd64.s
+++ b/src/runtime/asm_amd64.s
@@ -1600,7 +1600,9 @@ TEXT ·sigpanic0<ABIInternal>(SB),NOSPLIT,$0-0
 #ifdef GOEXPERIMENT_regabig
 	get_tls(R14)
 	MOVQ	g(R14), R14
+#ifndef GOOS_plan9
 	XORPS	X15, X15
+#endif
 #endif
 	JMP	·sigpanic<ABIInternal>(SB)