diff --git a/pkg/sentry/kernel/BUILD b/pkg/sentry/kernel/BUILD
index 773cb8c91..d9bbfb556 100644
--- a/pkg/sentry/kernel/BUILD
+++ b/pkg/sentry/kernel/BUILD
@@ -95,6 +95,8 @@ go_library(
         "posixtimer.go",
         "process_group_list.go",
         "ptrace.go",
+        "ptrace_amd64.go",
+        "ptrace_arm64.go",
         "rseq.go",
         "seccomp.go",
         "seqatomic_taskgoroutineschedinfo.go",
diff --git a/pkg/sentry/kernel/ptrace.go b/pkg/sentry/kernel/ptrace.go
index 20bac2b70..fa7a0d141 100644
--- a/pkg/sentry/kernel/ptrace.go
+++ b/pkg/sentry/kernel/ptrace.go
@@ -863,42 +863,6 @@ func (t *Task) Ptrace(req int64, pid ThreadID, addr, data usermem.Addr) error {
 		})
 		return err
 
-	case linux.PTRACE_PEEKUSR: // aka PTRACE_PEEKUSER
-		n, err := target.Arch().PtracePeekUser(uintptr(addr))
-		if err != nil {
-			return err
-		}
-		_, err = t.CopyOut(data, n)
-		return err
-
-	case linux.PTRACE_POKEUSR: // aka PTRACE_POKEUSER
-		return target.Arch().PtracePokeUser(uintptr(addr), uintptr(data))
-
-	case linux.PTRACE_GETREGS:
-		// "Copy the tracee's general-purpose ... registers ... to the address
-		// data in the tracer. ... (addr is ignored.) Note that SPARC systems
-		// have the meaning of data and addr reversed ..."
-		_, err := target.Arch().PtraceGetRegs(&usermem.IOReadWriter{
-			Ctx:  t,
-			IO:   t.MemoryManager(),
-			Addr: data,
-			Opts: usermem.IOOpts{
-				AddressSpaceActive: true,
-			},
-		})
-		return err
-
-	case linux.PTRACE_GETFPREGS:
-		_, err := target.Arch().PtraceGetFPRegs(&usermem.IOReadWriter{
-			Ctx:  t,
-			IO:   t.MemoryManager(),
-			Addr: data,
-			Opts: usermem.IOOpts{
-				AddressSpaceActive: true,
-			},
-		})
-		return err
-
 	case linux.PTRACE_GETREGSET:
 		// "Read the tracee's registers. addr specifies, in an
 		// architecture-dependent way, the type of registers to be read. ...
@@ -930,28 +894,6 @@ func (t *Task) Ptrace(req int64, pid ThreadID, addr, data usermem.Addr) error {
 		ar.End = end
 		return t.CopyOutIovecs(data, usermem.AddrRangeSeqOf(ar))
 
-	case linux.PTRACE_SETREGS:
-		_, err := target.Arch().PtraceSetRegs(&usermem.IOReadWriter{
-			Ctx:  t,
-			IO:   t.MemoryManager(),
-			Addr: data,
-			Opts: usermem.IOOpts{
-				AddressSpaceActive: true,
-			},
-		})
-		return err
-
-	case linux.PTRACE_SETFPREGS:
-		_, err := target.Arch().PtraceSetFPRegs(&usermem.IOReadWriter{
-			Ctx:  t,
-			IO:   t.MemoryManager(),
-			Addr: data,
-			Opts: usermem.IOOpts{
-				AddressSpaceActive: true,
-			},
-		})
-		return err
-
 	case linux.PTRACE_SETREGSET:
 		ars, err := t.CopyInIovecs(data, 1)
 		if err != nil {
@@ -1047,8 +989,9 @@ func (t *Task) Ptrace(req int64, pid ThreadID, addr, data usermem.Addr) error {
 		_, err := t.CopyOut(usermem.Addr(data), target.ptraceEventMsg)
 		return err
 
+	// PEEKSIGINFO is unimplemented but seems to have no users anywhere.
+
 	default:
-		// PEEKSIGINFO is unimplemented but seems to have no users anywhere.
-		return syserror.EIO
+		return t.ptraceArch(target, req, addr, data)
 	}
 }
diff --git a/pkg/sentry/kernel/ptrace_amd64.go b/pkg/sentry/kernel/ptrace_amd64.go
new file mode 100644
index 000000000..1f88efca3
--- /dev/null
+++ b/pkg/sentry/kernel/ptrace_amd64.go
@@ -0,0 +1,89 @@
+// Copyright 2019 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build amd64
+
+package kernel
+
+import (
+	"gvisor.googlesource.com/gvisor/pkg/abi/linux"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
+	"gvisor.googlesource.com/gvisor/pkg/syserror"
+)
+
+// ptraceArch implements arch-specific ptrace commands.
+func (t *Task) ptraceArch(target *Task, req int64, addr, data usermem.Addr) error {
+	switch req {
+	case linux.PTRACE_PEEKUSR: // aka PTRACE_PEEKUSER
+		n, err := target.Arch().PtracePeekUser(uintptr(addr))
+		if err != nil {
+			return err
+		}
+		_, err = t.CopyOut(data, n)
+		return err
+
+	case linux.PTRACE_POKEUSR: // aka PTRACE_POKEUSER
+		return target.Arch().PtracePokeUser(uintptr(addr), uintptr(data))
+
+	case linux.PTRACE_GETREGS:
+		// "Copy the tracee's general-purpose ... registers ... to the address
+		// data in the tracer. ... (addr is ignored.) Note that SPARC systems
+		// have the meaning of data and addr reversed ..."
+		_, err := target.Arch().PtraceGetRegs(&usermem.IOReadWriter{
+			Ctx:  t,
+			IO:   t.MemoryManager(),
+			Addr: data,
+			Opts: usermem.IOOpts{
+				AddressSpaceActive: true,
+			},
+		})
+		return err
+
+	case linux.PTRACE_GETFPREGS:
+		_, err := target.Arch().PtraceGetFPRegs(&usermem.IOReadWriter{
+			Ctx:  t,
+			IO:   t.MemoryManager(),
+			Addr: data,
+			Opts: usermem.IOOpts{
+				AddressSpaceActive: true,
+			},
+		})
+		return err
+
+	case linux.PTRACE_SETREGS:
+		_, err := target.Arch().PtraceSetRegs(&usermem.IOReadWriter{
+			Ctx:  t,
+			IO:   t.MemoryManager(),
+			Addr: data,
+			Opts: usermem.IOOpts{
+				AddressSpaceActive: true,
+			},
+		})
+		return err
+
+	case linux.PTRACE_SETFPREGS:
+		_, err := target.Arch().PtraceSetFPRegs(&usermem.IOReadWriter{
+			Ctx:  t,
+			IO:   t.MemoryManager(),
+			Addr: data,
+			Opts: usermem.IOOpts{
+				AddressSpaceActive: true,
+			},
+		})
+		return err
+
+	default:
+		return syserror.EIO
+	}
+}
diff --git a/pkg/sentry/kernel/ptrace_arm64.go b/pkg/sentry/kernel/ptrace_arm64.go
new file mode 100644
index 000000000..4636405e6
--- /dev/null
+++ b/pkg/sentry/kernel/ptrace_arm64.go
@@ -0,0 +1,28 @@
+// Copyright 2019 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build arm64
+
+package kernel
+
+import (
+	"gvisor.googlesource.com/gvisor/pkg/abi/linux"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
+	"gvisor.googlesource.com/gvisor/pkg/syserror"
+)
+
+// ptraceArch implements arch-specific ptrace commands.
+func (t *Task) ptraceArch(target *Task, req int64, addr, data usermem.Addr) error {
+	return syserror.EIO
+}