diff --git a/generate/generate.go b/generate/generate.go
index 9e0d132..5e85502 100644
--- a/generate/generate.go
+++ b/generate/generate.go
@@ -595,6 +595,13 @@ func (this *Generator) generateDecodeValue(typ Type, typeName, valueSource, tagS
 		this.pop()
 		nn, err = this.iprintf("}\n")
 		n += nn; if err != nil { return n, err }
+		nn, err = this.iprintf("if %s > uint64(tape.MaxStructureLength) {\n", lengthVar)
+		n += nn; if err != nil { return n, err }
+		this.push()
+			nn, err = this.iprintf("return n, tape.ErrTooLong\n")
+		this.pop()
+		nn, err = this.iprintf("}\n")
+		n += nn; if err != nil { return n, err }
 		nn, err = this.iprintf("buffer := make([]byte, int(%s))\n", lengthVar)
 		n += nn; if err != nil { return n, err }
 		nn, err = this.iprintf("nn, err = decoder.Read(buffer)\n")
@@ -697,6 +704,13 @@ func (this *Generator) generateDecodeBranch(hash [16]byte, typ Type, typeName st
 			lengthVar := this.newTemporaryVar("length")
 			nn, err := this.iprintf("var %s uint64\n", lengthVar)
 			n += nn; if err != nil { return n, err }
+			nn, err = this.iprintf("if %s > uint64(tape.MaxStructureLength) {\n", lengthVar)
+			n += nn; if err != nil { return n, err }
+			this.push()
+				nn, err = this.iprintf("return n, tape.ErrTooLong\n")
+			this.pop()
+			nn, err = this.iprintf("}\n")
+			n += nn; if err != nil { return n, err }
 			nn, err = this.iprintf("%s, nn, err = decoder.ReadUintN(int(tag.CN()))\n", lengthVar)
 			n += nn; if err != nil { return n, err }
 			nn, err = this.generateErrorCheck()
@@ -766,6 +780,13 @@ func (this *Generator) generateDecodeBranch(hash [16]byte, typ Type, typeName st
 			lengthVar := this.newTemporaryVar("length")
 			nn, err := this.iprintf("var %s uint64\n", lengthVar)
 			n += nn; if err != nil { return n, err }
+			nn, err = this.iprintf("if %s > uint64(tape.MaxStructureLength) {\n", lengthVar)
+			n += nn; if err != nil { return n, err }
+			this.push()
+				nn, err = this.iprintf("return n, tape.ErrTooLong\n")
+			this.pop()
+			nn, err = this.iprintf("}\n")
+			n += nn; if err != nil { return n, err }
 			nn, err = this.iprintf("%s, nn, err = decoder.ReadUintN(int(tag.CN()))\n", lengthVar)
 			n += nn; if err != nil { return n, err }
 			nn, err = this.generateErrorCheck()