diff --git a/cmd/protoc-gen-go/internal_gengo/well_known_types.go b/cmd/protoc-gen-go/internal_gengo/well_known_types.go
index 99f3e44..4fc1cd7 100644
--- a/cmd/protoc-gen-go/internal_gengo/well_known_types.go
+++ b/cmd/protoc-gen-go/internal_gengo/well_known_types.go
@@ -25,6 +25,9 @@
 		g.P("// If no options are specified, call dst.MarshalFrom instead.")
 		g.P("func MarshalFrom(dst *Any, src ", protoPackage.Ident("Message"), ", opts ", protoPackage.Ident("MarshalOptions"), ") error {")
 		g.P("	const urlPrefix = \"type.googleapis.com/\"")
+		g.P("	if src == nil {")
+		g.P("		return ", protoimplPackage.Ident("X"), ".NewError(\"invalid nil source message\")")
+		g.P("	}")
 		g.P("	b, err := opts.Marshal(src)")
 		g.P("	if err != nil {")
 		g.P("		return err")
@@ -41,6 +44,9 @@
 		g.P("//")
 		g.P("// If no options are specified, call src.UnmarshalTo instead.")
 		g.P("func UnmarshalTo(src *Any, dst ", protoPackage.Ident("Message"), ", opts ", protoPackage.Ident("UnmarshalOptions"), ") error {")
+		g.P("	if src.GetTypeUrl() == \"\" {")
+		g.P("		return ", protoimplPackage.Ident("X"), ".NewError(\"invalid empty type URL\")")
+		g.P("	}")
 		g.P("	if !src.MessageIs(dst) {")
 		g.P("		got := dst.ProtoReflect().Descriptor().FullName()")
 		g.P("		want := src.MessageName()")
diff --git a/types/known/anypb/any.pb.go b/types/known/anypb/any.pb.go
index 775d839..4a7f5bb 100644
--- a/types/known/anypb/any.pb.go
+++ b/types/known/anypb/any.pb.go
@@ -167,6 +167,9 @@
 // If no options are specified, call dst.MarshalFrom instead.
 func MarshalFrom(dst *Any, src proto.Message, opts proto.MarshalOptions) error {
 	const urlPrefix = "type.googleapis.com/"
+	if src == nil {
+		return protoimpl.X.NewError("invalid nil source message")
+	}
 	b, err := opts.Marshal(src)
 	if err != nil {
 		return err
@@ -182,6 +185,9 @@
 //
 // If no options are specified, call src.UnmarshalTo instead.
 func UnmarshalTo(src *Any, dst proto.Message, opts proto.UnmarshalOptions) error {
+	if src.GetTypeUrl() == "" {
+		return protoimpl.X.NewError("invalid empty type URL")
+	}
 	if !src.MessageIs(dst) {
 		got := dst.ProtoReflect().Descriptor().FullName()
 		want := src.MessageName()