diff --git a/loader/cgo.go b/loader/cgo.go
index bcd26b9f..07d7718b 100644
--- a/loader/cgo.go
+++ b/loader/cgo.go
@@ -145,8 +145,12 @@ func (p *Package) processCgo(filename string, f *ast.File, cflags []string) []er
 		// source location.
 		info.importCPos = spec.Path.ValuePos
 
-		pos := info.fset.PositionFor(genDecl.Doc.Pos(), true)
-		errs := info.parseFragment(cgoComment+cgoTypes, cflags, pos.Filename, pos.Line)
+		pos := genDecl.Pos()
+		if genDecl.Doc != nil {
+			pos = genDecl.Doc.Pos()
+		}
+		position := info.fset.PositionFor(pos, true)
+		errs := info.parseFragment(cgoComment+cgoTypes, cflags, position.Filename, position.Line)
 		if errs != nil {
 			return errs
 		}
diff --git a/testdata/cgo/main.go b/testdata/cgo/main.go
index 7a434855..e1e75700 100644
--- a/testdata/cgo/main.go
+++ b/testdata/cgo/main.go
@@ -7,6 +7,8 @@ int mul(int, int);
 */
 import "C"
 
+import "C"
+
 import "unsafe"
 
 func main() {