How to fix Error: Expected attribute terminator in Terraform

What this error means

This error occurs when Terraform's HCL parser encounters a syntax error while parsing resource or block attributes. The parser expects a specific terminator (usually a comma or closing brace) after an attribute definition but finds something unexpected instead. The "Expected attribute terminator" error is a parsing-level syntax error that indicates malformed HCL. Common causes include missing commas between attributes, unclosed strings or brackets, improper indentation in YAML-like blocks, or using invalid characters in attribute values without proper quoting. This is typically caught by terraform validate before any infrastructure changes are attempted, making it a configuration syntax issue rather than a resource creation problem.

Typical symptoms

• Terraform returns "Expected attribute terminator" error during terraform validate, plan, or apply
• Error message points to a specific line number in your configuration file
• The problematic line appears to have valid-looking attribute syntax
• Configuration validation fails immediately without attempting to parse further
• Error occurs when adding or modifying resource attributes
• Similar configurations work fine in other files or previous versions

Common causes

1. Missing comma between consecutive attributes in a resource or block definition
2. Unclosed or mismatched quotation marks around attribute values
3. Unmatched or incorrectly nested braces, brackets, or parentheses
4. Using tabs instead of spaces for indentation in nested blocks
5. Invalid characters in unquoted attribute values (e.g., special symbols, colons without string context)
6. Line break in the middle of a string value without proper string continuation
7. Incorrect syntax in map or list definitions without proper closing brackets

How to fix "Error: Expected attribute terminator"

terraform validate

# Wrong - missing comma after name
resource "aws_instance" "example" {
  ami           = "ami-12345"
  instance_type = "t2.micro"
  tags = {
    Name = "example"
  }
}

# Correct - comma between attributes
resource "aws_instance" "example" {
  ami           = "ami-12345"
  instance_type = "t2.micro",
  tags = {
    Name = "example"
  }
}

# Wrong - missing closing quote
resource "aws_instance" "example" {
  ami = "ami-12345
  instance_type = "t2.micro"
}

# Correct - properly quoted strings
resource "aws_instance" "example" {
  ami           = "ami-12345"
  instance_type = "t2.micro"
}

# Wrong - missing closing brace
resource "aws_instance" "example" {
  tags = {
    Name = "example"
    Environment = "prod"
}

# Correct - all braces closed
resource "aws_instance" "example" {
  tags = {
    Name = "example"
    Environment = "prod"
  }
}

# Use 2 or 4 spaces consistently
resource "aws_instance" "example" {
  ami           = "ami-12345"
  instance_type = "t2.micro"
}

# Also works with 4 spaces
resource "aws_instance" "example" {
    ami           = "ami-12345"
    instance_type = "t2.micro"
}

# Wrong - colon without quotes
ami = ami:123:456

# Correct - special characters quoted
ami = "ami:123:456"
description = "This is a description with: colons and - dashes"

# Wrong - missing comma in map
tags = {
  Name = "example"
  Env = "prod"
}

# Correct - comma between map entries
tags = {
  Name = "example",
  Env = "prod"
}

# Correct - list syntax (comma-separated values in brackets)
subnets = ["subnet-123", "subnet-456", "subnet-789"]

terraform validate

Advanced notes

Frequently asked questions

What does "Error: Expected attribute terminator" mean?

This error occurs when Terraform's HCL parser encounters a syntax error while parsing resource or block attributes. The parser expects a specific terminator (usually a comma or closing brace) after an attribute definition but finds something unexpected instead. The "Expected attribute terminator" error is a parsing-level syntax error that indicates malformed HCL.

How do I fix "Error: Expected attribute terminator"?

The Expected attribute terminator error occurs when Terraform's HCL parser encounters invalid syntax in a resource or block attribute definition. This typically happens due to missing commas, incorrect quotation marks, or improper line breaks. Fix it by reviewing your configuration syntax carefully using terraform validate.

What causes "Error: Expected attribute terminator"?

Missing comma between consecutive attributes in a resource or block definition Unclosed or mismatched quotation marks around attribute values Unmatched or incorrectly nested braces, brackets, or parentheses

Is the "Error: Expected attribute terminator" error serious?

Yes. This is a high-severity error that usually blocks work until it is fixed, but the steps above resolve it.

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• Error: External program failed to produce valid JSON

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• Error waiting for resource creation

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• context deadline exceeded

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Official resources & further reading

• 📚Terraform Official Documentation
• Terraform Troubleshooting Workflow - Official Tutorial
• Terraform Configuration Language Syntax - Official Documentation
• Terraform String Literals and Expressions - Official Documentation
• HCL2 Attribute Terminator Issues - GitHub Discussion
• How to Troubleshoot 5 Common Terraform Errors - Pluralsight