diff --git a/nixos/doc/manual/development/option-types.section.md b/nixos/doc/manual/development/option-types.section.md
index 7864b62605c2..40b4d78b250e 100644
--- a/nixos/doc/manual/development/option-types.section.md
+++ b/nixos/doc/manual/development/option-types.section.md
@@ -140,6 +140,11 @@ merging is handled.
 
 :   A floating point number.
 
+    ::: {.warning}
+    Converting a floating point number to a string with `toString` or `toJSON`
+    may result in [precision loss](https://github.com/NixOS/nix/issues/5733).
+    :::
+
 `types.number`
 
 :   Either a signed integer or a floating point number. No implicit conversion
diff --git a/nixos/doc/manual/from_md/development/option-types.section.xml b/nixos/doc/manual/from_md/development/option-types.section.xml
index e207b97a46f8..4036bc0ba743 100644
--- a/nixos/doc/manual/from_md/development/option-types.section.xml
+++ b/nixos/doc/manual/from_md/development/option-types.section.xml
@@ -256,6 +256,15 @@
             <para>
               A floating point number.
             </para>
+            <warning>
+              <para>
+                Converting a floating point number to a string with
+                <literal>toString</literal> or <literal>toJSON</literal>
+                may result in
+                <link xlink:href="https://github.com/NixOS/nix/issues/5733">precision
+                loss</link>.
+              </para>
+            </warning>
           </listitem>
         </varlistentry>
         <varlistentry>