diff --git a/docs/abi-spec.rst b/docs/abi-spec.rst
index ddffaf3f4..cf5ed9699 100644
--- a/docs/abi-spec.rst
+++ b/docs/abi-spec.rst
@@ -61,7 +61,7 @@ The following elementary types exist:
 - ``bool``: equivalent to ``uint8`` restricted to the values 0 and 1. For computing the function selector, ``bool`` is used.
 
 - ``fixed<M>x<N>``: signed fixed-point decimal number of ``M`` bits, ``8 <= M <= 256``,
-  ``M % 8 ==0``, and ``0 < N <= 80``, which denotes the value ``v`` as ``v / (10 ** N)``.
+  ``M % 8 == 0``, and ``0 < N <= 80``, which denotes the value ``v`` as ``v / (10 ** N)``.
 
 - ``ufixed<M>x<N>``: unsigned variant of ``fixed<M>x<N>``.
 
@@ -76,6 +76,9 @@ The following (fixed-size) array type exists:
 
 - ``<type>[M]``: a fixed-length array of ``M`` elements, ``M >= 0``, of the given type.
 
+    .. note::
+        While this ABI specification can express fixed-length arrays with zero elements, they're not supported by the compiler.
+
 The following non-fixed-size types exist:
 
 - ``bytes``: dynamic sized byte sequence.