src/cmd/go/internal/work/exec.go | 4 ++++

diff --git a/src/cmd/go/internal/work/exec.go b/src/cmd/go/internal/work/exec.go
index 6bfc83aae262116d2449f24af030654d77543b99..8c3bac51e66d0e677c1dbf0c81baa98f9d9e4fb7 100644
--- a/src/cmd/go/internal/work/exec.go
+++ b/src/cmd/go/internal/work/exec.go
@@ -3231,6 +3231,10 @@ }
 
 // Run SWIG on one SWIG input file.
 func (b *Builder) swigOne(a *Action, file, objdir string, pcCFLAGS []string, cxx bool, intgosize string) (outGo, outC string, err error) {
+	if strings.HasPrefix(file, "cgo") {
+		return "", "", errors.New("SWIG file must not use prefix 'cgo'")
+	}
+
 	p := a.Package
 	sh := b.Shell(a)