diff --git a/lib/gnucash/account.rb b/lib/gnucash/account.rb
index 71f1cd7..bb6f06b 100644
--- a/lib/gnucash/account.rb
+++ b/lib/gnucash/account.rb
@@ -2,20 +2,20 @@ module Gnucash
   # Represent a GnuCash account object
   class Account
     # _String_: The name of the account (unqualified)
-    attr_accessor :name
+    attr_reader :name
 
     # _String_: The account type (such as "EXPENSE")
-    attr_accessor :type
+    attr_reader :type
 
     # _String_: The GUID of the account
-    attr_accessor :id
+    attr_reader :id
 
     # _Array_: List of _AccountTransaction_ transactions associated with this
     # account.
-    attr_accessor :transactions
+    attr_reader :transactions
 
     # Boolean: whether the account is a placeholder or not
-    attr_accessor :placeholder
+    attr_reader :placeholder
 
     # Create an Account object.
     # === Arguments
diff --git a/lib/gnucash/account_transaction.rb b/lib/gnucash/account_transaction.rb
index 5c240a0..266ec05 100644
--- a/lib/gnucash/account_transaction.rb
+++ b/lib/gnucash/account_transaction.rb
@@ -2,7 +2,7 @@ module Gnucash
   # Class to link a transaction object to an Account.
   class AccountTransaction
     # _Gnucash::Value_: The transaction value for the linked account
-    attr_accessor :value
+    attr_reader :value
 
     # Construct an AccountTransaction object.
     # This method is used internally when building a Transaction object.
diff --git a/lib/gnucash/book.rb b/lib/gnucash/book.rb
index be4063b..9d49ee5 100644
--- a/lib/gnucash/book.rb
+++ b/lib/gnucash/book.rb
@@ -5,16 +5,16 @@ module Gnucash
   # Represent a GnuCash Book
   class Book
     # _Array_ of _Gnucash::Account_ objects in the book
-    attr_accessor :accounts
+    attr_reader :accounts
 
     # _Array_ of _Gnucash::Transaction_ objects in the book
-    attr_accessor :transactions
+    attr_reader :transactions
 
     # _String_ in "YYYY-MM-DD" format of the first transaction in the book
-    attr_accessor :start_date
+    attr_reader :start_date
 
     # _String_ in "YYYY-MM-DD" format of the last transaction in the book
-    attr_accessor :end_date
+    attr_reader :end_date
 
     # Construct a Book object.
     # Normally called internally by Gnucash.open()
diff --git a/lib/gnucash/transaction.rb b/lib/gnucash/transaction.rb
index ef5b6fa..de26914 100644
--- a/lib/gnucash/transaction.rb
+++ b/lib/gnucash/transaction.rb
@@ -5,16 +5,16 @@ module Gnucash
   # with an individual account.
   class Transaction
     # _String_: The date of the transaction, in ISO format ("YYYY-MM-DD")
-    attr_accessor :date
+    attr_reader :date
 
     # _String_: The GUID of the transaction
-    attr_accessor :id
+    attr_reader :id
 
     # _String_: The description of the transaction
-    attr_accessor :description
+    attr_reader :description
 
     # _Array_ of _Hash_ with keys +account+ and +value+
-    attr_accessor :splits
+    attr_reader :splits
 
     # Create a new Transaction object
     # === Arguments
diff --git a/lib/gnucash/value.rb b/lib/gnucash/value.rb
index d343b3a..6ff1ed0 100644
--- a/lib/gnucash/value.rb
+++ b/lib/gnucash/value.rb
@@ -5,7 +5,7 @@ module Gnucash
     include Comparable
 
     # _Fixnum_:: The raw, undivided integer value
-    attr_accessor :val
+    attr_reader :val
 
     # Create a new Value object with value 0
     def self.zero