diff --git a/go/loader/loader.go b/go/loader/loader.go
index 98df7aad..4503dd9e 100644
--- a/go/loader/loader.go
+++ b/go/loader/loader.go
@@ -313,6 +313,12 @@ func (conf *Config) addImport(path string, tests bool) {
 func (prog *Program) PathEnclosingInterval(start, end token.Pos) (pkg *PackageInfo, path []ast.Node, exact bool) {
 	for _, info := range prog.AllPackages {
 		for _, f := range info.Files {
+			if f.Pos() == token.NoPos {
+				// This can happen if the parser saw
+				// too many errors and bailed out.
+				// (Use parser.AllErrors to prevent that.)
+				continue
+			}
 			if !tokenFileContainsPos(prog.Fset.File(f.Pos()), start) {
 				continue
 			}
diff --git a/oracle/oracle.go b/oracle/oracle.go
index 4cdd2eca..65ac9edd 100644
--- a/oracle/oracle.go
+++ b/oracle/oracle.go
@@ -23,6 +23,7 @@ import (
 	"fmt"
 	"go/ast"
 	"go/build"
+	"go/parser"
 	"go/token"
 	"io"
 	"path/filepath"
@@ -282,6 +283,9 @@ func allowErrors(lconf *loader.Config) {
 	ctxt.CgoEnabled = false
 	lconf.Build = &ctxt
 	lconf.AllowErrors = true
+	// AllErrors makes the parser always return an AST instead of
+	// bailing out after 10 errors and returning an empty ast.File.
+	lconf.ParserMode = parser.AllErrors
 	lconf.TypeChecker.Error = func(err error) {}
 }