diff --git a/go.mod b/go.mod
index 6312e77dd7..fe2d42b84b 100644
--- a/go.mod
+++ b/go.mod
@@ -96,10 +96,13 @@ replace github.com/spf13/afero => github.com/aslilac/afero v0.0.0-20250403163713
 //    region the request is actually signed for.
 // 6) coder/fantasy#50, report per-request Anthropic usage at Finish so
 //    multi-iteration requests do not inflate context estimates.
-// 7) go.mod replaces pointing anthropic-sdk-go and openai-go at the
+// 7) coder/fantasy#52, keep the last usage-bearing chunk when an
+//    OpenAI-compatible stream ends with a usage-less finish chunk, so
+//    trailing chunks cannot zero reported usage.
+// 8) go.mod replaces pointing anthropic-sdk-go and openai-go at the
 //    coder forks below.
-// See: https://github.com/coder/fantasy/commits/6f8df3735907
-replace charm.land/fantasy => github.com/coder/fantasy v0.0.0-20260812075759-6f8df3735907
+// See: https://github.com/coder/fantasy/commits/833854abc543
+replace charm.land/fantasy => github.com/coder/fantasy v0.0.0-20260812122040-833854abc543
 
 // coder/coder uses a fork of charmbracelet's fork of the Anthropic Go SDK
 // with performance improvements and Bedrock header cleanup.
diff --git a/go.sum b/go.sum
index 8755033c4b..29f5022cc5 100644
--- a/go.sum
+++ b/go.sum
@@ -327,8 +327,8 @@ github.com/coder/bubbletea v1.2.2-0.20241212190825-007a1cdb2c41 h1:SBN/DA63+ZHwu
 github.com/coder/bubbletea v1.2.2-0.20241212190825-007a1cdb2c41/go.mod h1:I9ULxr64UaOSUv7hcb3nX4kowodJCVS7vt7VVJk/kW4=
 github.com/coder/clistat v1.2.1 h1:P9/10njXMyj5cWzIU5wkRsSy5LVQH49+tcGMsAgWX0w=
 github.com/coder/clistat v1.2.1/go.mod h1:m7SC0uj88eEERgvF8Kn6+w6XF21BeSr+15f7GoLAw0A=
-github.com/coder/fantasy v0.0.0-20260812075759-6f8df3735907 h1:Mirl1lw+0MsndEL0feesyIqtxTdpiKrR8AH4zcA6SZU=
-github.com/coder/fantasy v0.0.0-20260812075759-6f8df3735907/go.mod h1:lcL8B/uroFq5YDHNFij2an0yarOtD7C3rmzD31i8oTA=
+github.com/coder/fantasy v0.0.0-20260812122040-833854abc543 h1:GDVwVOgilrtKfUZGN0L2hANHJbQEL0R1gBNYMJ0TnMA=
+github.com/coder/fantasy v0.0.0-20260812122040-833854abc543/go.mod h1:lcL8B/uroFq5YDHNFij2an0yarOtD7C3rmzD31i8oTA=
 github.com/coder/flog v1.1.0 h1:kbAes1ai8fIS5OeV+QAnKBQE22ty1jRF/mcAwHpLBa4=
 github.com/coder/flog v1.1.0/go.mod h1:UQlQvrkJBvnRGo69Le8E24Tcl5SJleAAR7gYEHzAmdQ=
 github.com/coder/go-httpstat v0.0.0-20230801153223-321c88088322 h1:m0lPZjlQ7vdVpRBPKfYIFlmgevoTkBxB10wv6l2gOaU=