diff --git a/include/etl/indirect_vector.h b/include/etl/indirect_vector.h
index b8806caa..cee9f9c5 100644
--- a/include/etl/indirect_vector.h
+++ b/include/etl/indirect_vector.h
@@ -606,6 +606,7 @@ namespace etl
     //*********************************************************************
     void reserve(size_t n)
     {
+      (void)n;  // Stop 'unused parameter' warning in release mode.
       ETL_ASSERT(n <= capacity(), ETL_ERROR(vector_out_of_bounds));
     }
 
diff --git a/include/etl/vector.h b/include/etl/vector.h
index 970f82ae..80994bd5 100644
--- a/include/etl/vector.h
+++ b/include/etl/vector.h
@@ -269,6 +269,7 @@ namespace etl
     //*********************************************************************
     void reserve(size_t n)
     {
+      (void)n; // Stop 'unused parameter' warning in release mode.
       ETL_ASSERT(n <= CAPACITY, ETL_ERROR(vector_out_of_bounds));
     }