diff --git a/README.md b/README.md
index c71c6fc..25dd4f1 100644
--- a/README.md
+++ b/README.md
@@ -282,6 +282,10 @@ That’s it! You now have a wonderfully compliant JSON:API exposing your wonderf
 Release notes
 -------------
 
+### 0.8.4 (2020-06-08)
+
+* More robust workaround workaround for [giraffe-fsharp/Giraffe#24](https://github.com/giraffe-fsharp/Giraffe/issues/424)
+
 ### 0.8.3 (2020-06-05)
 
 * Added workaround for [giraffe-fsharp/Giraffe#24](https://github.com/giraffe-fsharp/Giraffe/issues/424)
diff --git a/src/Felicity/Felicity.fsproj b/src/Felicity/Felicity.fsproj
index c37bb77..2c336d9 100644
--- a/src/Felicity/Felicity.fsproj
+++ b/src/Felicity/Felicity.fsproj
@@ -13,8 +13,8 @@
     <PackageLicenseExpression>MIT</PackageLicenseExpression>
     <PackageTags>f# fsharp jsonapi json-api json:api api rest rest-api api-rest api-server api-client web-api asp-net-core aspnetcore giraffe framework</PackageTags>
     <PackageIcon>felicity-logo-128x128.png</PackageIcon>
-    <Version>0.8.3</Version>
-    <PackageReleaseNotes>Added workaround for Giraffe bug (https://github.com/giraffe-fsharp/Giraffe/issues/424)</PackageReleaseNotes>
+    <Version>0.8.4</Version>
+    <PackageReleaseNotes>More robust workaround for Giraffe bug (https://github.com/giraffe-fsharp/Giraffe/issues/424)</PackageReleaseNotes>
   </PropertyGroup>
 
   <PropertyGroup>
diff --git a/src/Felicity/Operations.fs b/src/Felicity/Operations.fs
index bb509f8..a4cabab 100644
--- a/src/Felicity/Operations.fs
+++ b/src/Felicity/Operations.fs
@@ -34,7 +34,7 @@ type Preconditions<'ctx, 'entity> = internal {
       let lastModified =
         this.getLastModified ctx (unbox<'entity> entity)
         // Workaround for https://github.com/giraffe-fsharp/Giraffe/issues/424
-        |> Option.map (fun dt -> dt.AddMilliseconds (float (-dt.Millisecond)))
+        |> Option.map (fun dt -> dt.AddTicks(-(dt.Ticks % TimeSpan.TicksPerSecond)))
       let res = httpCtx.ValidatePreconditions eTag lastModified
       // Clear headers because response-level ETag/Last-Modified headers don't
       // necessarily make sense in JSON:API due to compound documents; these values