diff --git a/rule/cognitive-complexity.go b/rule/cognitive-complexity.go
index 711aa22..9b98237 100644
--- a/rule/cognitive-complexity.go
+++ b/rule/cognitive-complexity.go
@@ -52,7 +52,7 @@ type cognitiveComplexityLinter struct {
 func (w cognitiveComplexityLinter) lint() {
 	f := w.file
 	for _, decl := range f.AST.Decls {
-		if fn, ok := decl.(*ast.FuncDecl); ok {
+		if fn, ok := decl.(*ast.FuncDecl); ok && fn.Body != nil {
 			v := cognitiveComplexityVisitor{}
 			c := v.subTreeComplexity(fn.Body)
 			if c > w.maxComplexity {
diff --git a/testdata/cognitive-complexity.go b/testdata/cognitive-complexity.go
index 0a0348a..c20794b 100644
--- a/testdata/cognitive-complexity.go
+++ b/testdata/cognitive-complexity.go
@@ -278,3 +278,6 @@ func (m *Migrator) MigrateIfNeeded(target *EtcdVersionPair) error { // MATCH /fu
 		}
 	}
 }
+
+// no regression test for issue #451
+func myFunc()