diff --git a/go/internal/packagesdriver/sizes.go b/go/internal/packagesdriver/sizes.go
index eecf07f..fdc7da0 100644
--- a/go/internal/packagesdriver/sizes.go
+++ b/go/internal/packagesdriver/sizes.go
@@ -86,6 +86,9 @@
 		return nil, err
 	}
 	fields := strings.Fields(stdout.String())
+	if len(fields) < 2 {
+		return nil, fmt.Errorf("could not determine GOARCH and Go compiler")
+	}
 	goarch := fields[0]
 	compiler := fields[1]
 	return types.SizesFor(compiler, goarch), nil