diff --git a/server/errors.go b/server/errors.go
index 93213785..d10474bd 100644
--- a/server/errors.go
+++ b/server/errors.go
@@ -261,7 +261,7 @@ func errorsUnwrap(err error) error {
 
 // implements: go 1.13 errors.Is(err, target error) bool
 // TODO replace with native code once we no longer support go1.12
-func IsErr(err, target error) bool {
+func ErrorIs(err, target error) bool {
 	// this is an outright copy of go 1.13 errors.Is(err, target error) bool
 	// removed isComparable
 	if err == nil || target == nil {
diff --git a/server/errors_test.go b/server/errors_test.go
index 76997357..2b43c4e8 100644
--- a/server/errors_test.go
+++ b/server/errors_test.go
@@ -28,7 +28,7 @@ func TestErrCtx(t *testing.T) {
 	if e == ErrWrongGateway {
 		t.Fatalf("%v and %v can't be compared this way", e, ErrWrongGateway)
 	}
-	if !IsErr(e, ErrWrongGateway) {
+	if !ErrorIs(e, ErrWrongGateway) {
 		t.Fatalf("%s and %s ", e, ErrWrongGateway)
 	}
 	if UnpackIfErrorCtx(ErrWrongGateway) != ErrWrongGateway.Error() {
@@ -55,7 +55,7 @@ func TestErrCtxWrapped(t *testing.T) {
 	if e == ErrWrongGateway {
 		t.Fatalf("%v and %v can't be compared this way", e, ErrWrongGateway)
 	}
-	if !IsErr(e, ErrWrongGateway) {
+	if !ErrorIs(e, ErrWrongGateway) {
 		t.Fatalf("%s and %s ", e, ErrWrongGateway)
 	}
 	if UnpackIfErrorCtx(ErrWrongGateway) != ErrWrongGateway.Error() {
diff --git a/server/parser_test.go b/server/parser_test.go
index fbaa81c9..7f2aece9 100644
--- a/server/parser_test.go
+++ b/server/parser_test.go
@@ -582,7 +582,7 @@ func TestMaxControlLine(t *testing.T) {
 
 	pub := []byte("PUB foo.bar 11\r")
 	err := c.parse(pub)
-	if !IsErr(err, ErrMaxControlLine) {
+	if !ErrorIs(err, ErrMaxControlLine) {
 		t.Fatalf("Expected an error parsing longer than expected control line")
 	}
 }