diff --git a/ConcurrentSeparationLogic.v b/ConcurrentSeparationLogic.v
index 05f83ba..6415b91 100644
--- a/ConcurrentSeparationLogic.v
+++ b/ConcurrentSeparationLogic.v
@@ -1,5 +1,5 @@
 (** Formal Reasoning About Programs <http://adam.chlipala.net/frap/>
-  * Chapter 19: Concurrent Separation Logic
+  * Chapter 20: Concurrent Separation Logic
   * Author: Adam Chlipala
   * License: https://creativecommons.org/licenses/by-nc-nd/4.0/ *)
 
diff --git a/Connecting.v b/Connecting.v
index 8624407..c25fdee 100644
--- a/Connecting.v
+++ b/Connecting.v
@@ -1,5 +1,5 @@
 (** Formal Reasoning About Programs <http://adam.chlipala.net/frap/>
-  * Chapter 16: Connecting to Real-World Programming Languages and Platforms
+  * Chapter 17: Connecting to Real-World Programming Languages and Platforms
   * Author: Adam Chlipala
   * License: https://creativecommons.org/licenses/by-nc-nd/4.0/ *)
 
diff --git a/DeepAndShallowEmbeddings.v b/DeepAndShallowEmbeddings.v
index 57e98d2..ec1b18d 100644
--- a/DeepAndShallowEmbeddings.v
+++ b/DeepAndShallowEmbeddings.v
@@ -1,5 +1,5 @@
 (** Formal Reasoning About Programs <http://adam.chlipala.net/frap/>
-  * Chapter 14: Deep and Shallow Embeddings
+  * Chapter 15: Deep and Shallow Embeddings
   * Author: Adam Chlipala
   * License: https://creativecommons.org/licenses/by-nc-nd/4.0/ *)
 
diff --git a/HoareLogic.v b/HoareLogic.v
index a73f190..1ca0273 100644
--- a/HoareLogic.v
+++ b/HoareLogic.v
@@ -1,5 +1,5 @@
 (** Formal Reasoning About Programs <http://adam.chlipala.net/frap/>
-  * Chapter 13: Hoare Logic: Verifying Imperative Programs
+  * Chapter 14: Hoare Logic: Verifying Imperative Programs
   * Author: Adam Chlipala
   * License: https://creativecommons.org/licenses/by-nc-nd/4.0/ *)
 
diff --git a/MessagesAndRefinement.v b/MessagesAndRefinement.v
index 5756fbb..0e3238a 100644
--- a/MessagesAndRefinement.v
+++ b/MessagesAndRefinement.v
@@ -1,5 +1,5 @@
 (** Formal Reasoning About Programs <http://adam.chlipala.net/frap/>
-  * Chapter 20: Process Algebra and Behavioral Refinement
+  * Chapter 21: Process Algebra and Behavioral Refinement
   * Author: Adam Chlipala
   * License: https://creativecommons.org/licenses/by-nc-nd/4.0/ *)
 
diff --git a/ProgramDerivation.v b/ProgramDerivation.v
index bb0d3c1..0575b30 100644
--- a/ProgramDerivation.v
+++ b/ProgramDerivation.v
@@ -1,5 +1,5 @@
 (** Formal Reasoning About Programs <http://adam.chlipala.net/frap/>
-  * Chapter 17: Deriving Programs from Specifications
+  * Chapter 18: Deriving Programs from Specifications
   * Author: Adam Chlipala
   * License: https://creativecommons.org/licenses/by-nc-nd/4.0/
   * Some material borrowed from Fiat <http://plv.csail.mit.edu/fiat/> *)
diff --git a/SeparationLogic.v b/SeparationLogic.v
index 492ac35..7368414 100644
--- a/SeparationLogic.v
+++ b/SeparationLogic.v
@@ -1,5 +1,5 @@
 (** Formal Reasoning About Programs <http://adam.chlipala.net/frap/>
-  * Chapter 15: Separation Logic
+  * Chapter 16: Separation Logic
   * Author: Adam Chlipala
   * License: https://creativecommons.org/licenses/by-nc-nd/4.0/ *)
 
diff --git a/SessionTypes.v b/SessionTypes.v
index f11a70a..c62cea0 100644
--- a/SessionTypes.v
+++ b/SessionTypes.v
@@ -1,5 +1,5 @@
 (** Formal Reasoning About Programs <http://adam.chlipala.net/frap/>
-  * Chapter 21: Session Types
+  * Chapter 22: Session Types
   * Author: Adam Chlipala
   * License: https://creativecommons.org/licenses/by-nc-nd/4.0/ *)
 
diff --git a/SharedMemory.v b/SharedMemory.v
index 68f3df4..822d809 100644
--- a/SharedMemory.v
+++ b/SharedMemory.v
@@ -1,5 +1,5 @@
 (** Formal Reasoning About Programs <http://adam.chlipala.net/frap/>
-  * Chapter 18: Operational Semantics for Shared-Memory Concurrency
+  * Chapter 19: Operational Semantics for Shared-Memory Concurrency
   * Author: Adam Chlipala
   * License: https://creativecommons.org/licenses/by-nc-nd/4.0/ *)
 
diff --git a/TypesAndMutation.v b/TypesAndMutation.v
index 5da5627..e563fa3 100644
--- a/TypesAndMutation.v
+++ b/TypesAndMutation.v
@@ -1,5 +1,5 @@
 (** Formal Reasoning About Programs <http://adam.chlipala.net/frap/>
-  * Chapter 12: Types and Mutation
+  * Chapter 13: Types and Mutation
   * Author: Adam Chlipala
   * License: https://creativecommons.org/licenses/by-nc-nd/4.0/ *)