diff --git a/src/cmd/compile/internal/gc/subr.go b/src/cmd/compile/internal/gc/subr.go
index eccd6f8a74..defefd76b3 100644
--- a/src/cmd/compile/internal/gc/subr.go
+++ b/src/cmd/compile/internal/gc/subr.go
@@ -1854,8 +1854,10 @@ func isdirectiface(t *types.Type) bool {
 	}
 
 	switch t.Etype {
-	case TPTR,
-		TCHAN,
+	case TPTR:
+		// Pointers to notinheap types must be stored indirectly. See issue 42076.
+		return !t.Elem().NotInHeap()
+	case TCHAN,
 		TMAP,
 		TFUNC,
 		TUNSAFEPTR:
diff --git a/src/cmd/compile/internal/gc/typecheck.go b/src/cmd/compile/internal/gc/typecheck.go
index ce817db446..8ebeaf1330 100644
--- a/src/cmd/compile/internal/gc/typecheck.go
+++ b/src/cmd/compile/internal/gc/typecheck.go
@@ -2516,7 +2516,7 @@ func lookdot(n *Node, t *types.Type, dostrcmp int) *types.Field {
 				n.Left = nod(OADDR, n.Left, nil)
 				n.Left.SetImplicit(true)
 				n.Left = typecheck(n.Left, ctxType|ctxExpr)
-			} else if tt.IsPtr() && !rcvr.IsPtr() && types.Identical(tt.Elem(), rcvr) {
+			} else if tt.IsPtr() && (!rcvr.IsPtr() || rcvr.IsPtr() && rcvr.Elem().NotInHeap()) && types.Identical(tt.Elem(), rcvr) {
 				n.Left = nod(ODEREF, n.Left, nil)
 				n.Left.SetImplicit(true)
 				n.Left = typecheck(n.Left, ctxType|ctxExpr)
diff --git a/src/reflect/deepequal.go b/src/reflect/deepequal.go
index be66464129..d951d8d999 100644
--- a/src/reflect/deepequal.go
+++ b/src/reflect/deepequal.go
@@ -35,7 +35,17 @@ func deepValueEqual(v1, v2 Value, visited map[visit]bool) bool {
 	// and it's safe and valid to get Value's internal pointer.
 	hard := func(v1, v2 Value) bool {
 		switch v1.Kind() {
-		case Map, Slice, Ptr, Interface:
+		case Ptr:
+			if v1.typ.ptrdata == 0 {
+				// go:notinheap pointers can't be cyclic.
+				// At least, all of our current uses of go:notinheap have
+				// that property. The runtime ones aren't cyclic (and we don't use
+				// DeepEqual on them anyway), and the cgo-generated ones are
+				// all empty structs.
+				return false
+			}
+			fallthrough
+		case Map, Slice, Interface:
 			// Nil pointers cannot be cyclic. Avoid putting them in the visited map.
 			return !v1.IsNil() && !v2.IsNil()
 		}
diff --git a/src/reflect/value.go b/src/reflect/value.go
index bb6371b867..24eab6a2c6 100644
--- a/src/reflect/value.go
+++ b/src/reflect/value.go
@@ -90,6 +90,7 @@ func (f flag) ro() flag {
 
 // pointer returns the underlying pointer represented by v.
 // v.Kind() must be Ptr, Map, Chan, Func, or UnsafePointer
+// if v.Kind() == Ptr, the base type must not be go:notinheap.
 func (v Value) pointer() unsafe.Pointer {
 	if v.typ.size != ptrSize || !v.typ.pointers() {
 		panic("can't call pointer on a non-pointer Value")
@@ -1453,7 +1454,16 @@ func (v Value) Pointer() uintptr {
 	// TODO: deprecate
 	k := v.kind()
 	switch k {
-	case Chan, Map, Ptr, UnsafePointer:
+	case Ptr:
+		if v.typ.ptrdata == 0 {
+			// Handle pointers to go:notinheap types directly,
+			// so we never materialize such pointers as an
+			// unsafe.Pointer. (Such pointers are always indirect.)
+			// See issue 42076.
+			return *(*uintptr)(v.ptr)
+		}
+		fallthrough
+	case Chan, Map, UnsafePointer:
 		return uintptr(v.pointer())
 	case Func:
 		if v.flag&flagMethod != 0 {
diff --git a/src/runtime/netpoll.go b/src/runtime/netpoll.go
index 34ea82a7fa..77eb3aa4c6 100644
--- a/src/runtime/netpoll.go
+++ b/src/runtime/netpoll.go
@@ -79,16 +79,17 @@ type pollDesc struct {
 	lock    mutex // protects the following fields
 	fd      uintptr
 	closing bool
-	everr   bool    // marks event scanning error happened
-	user    uint32  // user settable cookie
-	rseq    uintptr // protects from stale read timers
-	rg      uintptr // pdReady, pdWait, G waiting for read or nil
-	rt      timer   // read deadline timer (set if rt.f != nil)
-	rd      int64   // read deadline
-	wseq    uintptr // protects from stale write timers
-	wg      uintptr // pdReady, pdWait, G waiting for write or nil
-	wt      timer   // write deadline timer
-	wd      int64   // write deadline
+	everr   bool      // marks event scanning error happened
+	user    uint32    // user settable cookie
+	rseq    uintptr   // protects from stale read timers
+	rg      uintptr   // pdReady, pdWait, G waiting for read or nil
+	rt      timer     // read deadline timer (set if rt.f != nil)
+	rd      int64     // read deadline
+	wseq    uintptr   // protects from stale write timers
+	wg      uintptr   // pdReady, pdWait, G waiting for write or nil
+	wt      timer     // write deadline timer
+	wd      int64     // write deadline
+	self    *pollDesc // storage for indirect interface. See (*pollDesc).makeArg.
 }
 
 type pollCache struct {
@@ -157,6 +158,7 @@ func poll_runtime_pollOpen(fd uintptr) (*pollDesc, int) {
 	pd.wseq++
 	pd.wg = 0
 	pd.wd = 0
+	pd.self = pd
 	unlock(&pd.lock)
 
 	var errno int32
@@ -271,14 +273,14 @@ func poll_runtime_pollSetDeadline(pd *pollDesc, d int64, mode int) {
 			// Copy current seq into the timer arg.
 			// Timer func will check the seq against current descriptor seq,
 			// if they differ the descriptor was reused or timers were reset.
-			pd.rt.arg = pd
+			pd.rt.arg = pd.makeArg()
 			pd.rt.seq = pd.rseq
 			resettimer(&pd.rt, pd.rd)
 		}
 	} else if pd.rd != rd0 || combo != combo0 {
 		pd.rseq++ // invalidate current timers
 		if pd.rd > 0 {
-			modtimer(&pd.rt, pd.rd, 0, rtf, pd, pd.rseq)
+			modtimer(&pd.rt, pd.rd, 0, rtf, pd.makeArg(), pd.rseq)
 		} else {
 			deltimer(&pd.rt)
 			pd.rt.f = nil
@@ -287,14 +289,14 @@ func poll_runtime_pollSetDeadline(pd *pollDesc, d int64, mode int) {
 	if pd.wt.f == nil {
 		if pd.wd > 0 && !combo {
 			pd.wt.f = netpollWriteDeadline
-			pd.wt.arg = pd
+			pd.wt.arg = pd.makeArg()
 			pd.wt.seq = pd.wseq
 			resettimer(&pd.wt, pd.wd)
 		}
 	} else if pd.wd != wd0 || combo != combo0 {
 		pd.wseq++ // invalidate current timers
 		if pd.wd > 0 && !combo {
-			modtimer(&pd.wt, pd.wd, 0, netpollWriteDeadline, pd, pd.wseq)
+			modtimer(&pd.wt, pd.wd, 0, netpollWriteDeadline, pd.makeArg(), pd.wseq)
 		} else {
 			deltimer(&pd.wt)
 			pd.wt.f = nil
@@ -547,3 +549,20 @@ func (c *pollCache) alloc() *pollDesc {
 	unlock(&c.lock)
 	return pd
 }
+
+// makeArg converts pd to an interface{}.
+// makeArg does not do any allocation. Normally, such
+// a conversion requires an allocation because pointers to
+// go:notinheap types (which pollDesc is) must be stored
+// in interfaces indirectly. See issue 42076.
+func (pd *pollDesc) makeArg() (i interface{}) {
+	x := (*eface)(unsafe.Pointer(&i))
+	x._type = pdType
+	x.data = unsafe.Pointer(&pd.self)
+	return
+}
+
+var (
+	pdEface interface{} = (*pollDesc)(nil)
+	pdType  *_type      = efaceOf(&pdEface)._type
+)
diff --git a/test/fixedbugs/issue42076.go b/test/fixedbugs/issue42076.go
new file mode 100644
index 0000000000..3e954813c9
--- /dev/null
+++ b/test/fixedbugs/issue42076.go
@@ -0,0 +1,21 @@
+// run
+
+// Copyright 2020 The Go Authors. All rights reserved.  Use of this
+// source code is governed by a BSD-style license that can be found in
+// the LICENSE file.
+
+package main
+
+import "reflect"
+
+//go:notinheap
+type NIH struct {
+}
+
+var x, y NIH
+
+func main() {
+	if reflect.DeepEqual(&x, &y) != true {
+		panic("should report true")
+	}
+}