diff --git a/bramble-core/src/main/java/org/briarproject/bramble/crypto/CryptoModule.java b/bramble-core/src/main/java/org/briarproject/bramble/crypto/CryptoModule.java
index 8f0299441ced948ad754374d1ed5c0d0280f0fd2..5ab4becce5b58fba195864c63654b2d5d2043b8d 100644
--- a/bramble-core/src/main/java/org/briarproject/bramble/crypto/CryptoModule.java
+++ b/bramble-core/src/main/java/org/briarproject/bramble/crypto/CryptoModule.java
@@ -37,6 +37,9 @@ public class CryptoModule {
 
 	/**
 	 * The maximum number of executor threads.
+	 * <p>
+	 * The number of available processors can change during the lifetime of the
+	 * JVM, so this is just a reasonable guess.
 	 */
 	private static final int MAX_EXECUTOR_THREADS =
 			Math.max(1, Runtime.getRuntime().availableProcessors() - 1);
diff --git a/bramble-core/src/main/java/org/briarproject/bramble/sync/SyncModule.java b/bramble-core/src/main/java/org/briarproject/bramble/sync/SyncModule.java
index eea0e2d3bb2299ae57b3f12c8df659e5dbdad3a0..ca6ec897af315954beb53279a1a7c8df794808a3 100644
--- a/bramble-core/src/main/java/org/briarproject/bramble/sync/SyncModule.java
+++ b/bramble-core/src/main/java/org/briarproject/bramble/sync/SyncModule.java
@@ -34,6 +34,9 @@ public class SyncModule {
 	/**
 	 * The maximum number of validation tasks to delegate to the crypto
 	 * executor concurrently.
+	 * <p>
+	 * The number of available processors can change during the lifetime of the
+	 * JVM, so this is just a reasonable guess.
 	 */
 	private static final int MAX_CONCURRENT_VALIDATION_TASKS =
 			Math.max(1, Runtime.getRuntime().availableProcessors() - 1);