diff --git a/docs/core/definitions/algebra.rst b/docs/core/definitions/algebra.rst
index 9d35ef34992..7beb81f7ad7 100644
--- a/docs/core/definitions/algebra.rst
+++ b/docs/core/definitions/algebra.rst
@@ -2,12 +2,12 @@ Algebra definitions
 ===================
 
 The main algebra classes for ACTS are defined in the `Acts/Definitions/Algebra.hpp` header file.
-The basic scalar type can be defined via this file and is set per default to `double`, however, if `ACTS_CUSTOM_SCALAR` is set it will be used instead.
+The basic scalar type can be defined via this file and is set per default to `double`, however, if `ACTS_CUSTOM_SCALARTYPE` is set it will be used instead.
 
 .. code-block:: cpp
 
-   #ifdef ACTS_CUSTOM_SCALAR
-   using ActsScalar = ACTS_CUSTOM_SCALAR;
+   #ifdef ACTS_CUSTOM_SCALARTYPE
+   using ActsScalar = ACTS_CUSTOM_SCALARTYPE;
    #else
    using ActsScalar = double;
    #endif