diff --git a/lint.go b/lint.go
index add19b9..dffff3f 100644
--- a/lint.go
+++ b/lint.go
@@ -280,6 +280,23 @@
 				return true
 			}
 			check(v.Name, "func")
+
+			checkList := func(fl *ast.FieldList, thing string) {
+				if fl == nil {
+					return
+				}
+				for _, f := range fl.List {
+					for _, id := range f.Names {
+						check(id, thing)
+					}
+				}
+			}
+			thing := "func"
+			if v.Recv != nil {
+				thing = "method"
+			}
+			checkList(v.Type.Params, thing+" parameter")
+			checkList(v.Type.Results, thing+" result")
 		case *ast.GenDecl:
 			if v.Tok == token.IMPORT {
 				return true
diff --git a/testdata/names.go b/testdata/names.go
index f38a694..e923980 100644
--- a/testdata/names.go
+++ b/testdata/names.go
@@ -26,3 +26,8 @@
 	HTML  = 3 // okay; no underscore
 	X509B = 4 // ditto
 )
+
+func f(bad_name int)                    {} // MATCH /underscore.*func parameter.*bad_name/
+func g() (no_way int)                   {} // MATCH /underscore.*func result.*no_way/
+func (t *t_wow) f(more_under string)    {} // MATCH /underscore.*method parameter.*more_under/
+func (t *t_wow) g() (still_more string) {} // MATCH /underscore.*method result.*still_more/