diff --git a/encode.go b/encode.go
index 1fff880..eb2f1e3 100644
--- a/encode.go
+++ b/encode.go
@@ -164,6 +164,7 @@ func (e *Encoder) encode(v interface{}) error {
 		}
 		ctx := codeSet.ctx.Get().(*encodeRuntimeContext)
 		p := uintptr(header.ptr)
+		ctx.reset()
 		ctx.init(p)
 		err := e.run(ctx, code)
 		if e.enabledIndent {
@@ -218,6 +219,7 @@ func (e *Encoder) encode(v interface{}) error {
 	cachedOpcode.set(typeptr, codeSet)
 	p := uintptr(header.ptr)
 	ctx := codeSet.ctx.Get().(*encodeRuntimeContext)
+	ctx.reset()
 	ctx.init(p)
 	if e.enabledIndent {
 		err := e.run(ctx, codeIndent)
diff --git a/encode_context.go b/encode_context.go
index da3d233..0c7ee1b 100644
--- a/encode_context.go
+++ b/encode_context.go
@@ -63,6 +63,10 @@ type encodeRuntimeContext struct {
 	seenPtr map[uintptr]struct{}
 }
 
+func (c *encodeRuntimeContext) reset() {
+	c.seenPtr = map[uintptr]struct{}{}
+}
+
 func (c *encodeRuntimeContext) init(p uintptr) {
 	c.ptrs[0] = p
 }