diff --git a/src/cmd/compile/internal/noder/noder.go b/src/cmd/compile/internal/noder/noder.go
index fc1541f..b36db67 100644
--- a/src/cmd/compile/internal/noder/noder.go
+++ b/src/cmd/compile/internal/noder/noder.go
@@ -323,8 +323,7 @@
 		}
 		n := ir.AsNode(typecheck.Lookup(l.local).Def)
 		if n == nil || n.Op() != ir.ONAME {
-			// TODO(mdempsky): Change to p.errorAt before Go 1.17 release.
-			// base.WarnfAt(p.makeXPos(l.pos), "//go:linkname must refer to declared function or variable (will be an error in Go 1.17)")
+			p.errorAt(l.pos, "//go:linkname must refer to declared function or variable")
 			continue
 		}
 		if n.Sym().Linkname != "" {
diff --git a/src/cmd/cover/testdata/test.go b/src/cmd/cover/testdata/test.go
index b794962..703fba5 100644
--- a/src/cmd/cover/testdata/test.go
+++ b/src/cmd/cover/testdata/test.go
@@ -13,6 +13,7 @@
 import _ "unsafe" // for go:linkname
 
 //go:linkname some_name some_name
+var some_name int
 
 const anything = 1e9 // Just some unlikely value that means "we got here, don't care how often"
 
diff --git a/test/linkname2.go b/test/linkname2.go
index 43e66a5..cb7f9be 100644
--- a/test/linkname2.go
+++ b/test/linkname2.go
@@ -16,13 +16,10 @@
 //go:linkname x ok
 
 // ERROR "//go:linkname requires linkname argument or -p compiler flag"
-// BAD: want error "//go:linkname must refer to declared function or variable"
-// BAD: want error "//go:linkname must refer to declared function or variable"
+// ERROR "//go:linkname must refer to declared function or variable"
+// ERROR "//go:linkname must refer to declared function or variable"
 // ERROR "duplicate //go:linkname for x"
 
-// The two BAD lines are just waiting for #42938 before we can
-// re-enable the errors.
-
 //line linkname2.go:18
 //go:linkname y
 //go:linkname nonexist nonexist