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 8e302766711ea4c85c5b10b3dc80c245e706bc8f..01591c9c9bbceb78be6bf23b52483507682c89f0 100644
--- a/src/cmd/go/internal/work/exec.go
+++ b/src/cmd/go/internal/work/exec.go
@@ -3455,6 +3455,10 @@ }
 
 // Run SWIG on one SWIG input file.
 func (b *Builder) swigOne(a *Action, file, objdir string, pcCFLAGS []string, cxx bool, intgosize string) error {
+	if strings.HasPrefix(file, "cgo") {
+		return errors.New("SWIG file must not use prefix 'cgo'")
+	}
+
 	p := a.Package
 	sh := b.Shell(a)