diff --git a/dub.json b/dub.json
index 61a7955..6f2d45c 100644
--- a/dub.json
+++ b/dub.json
@@ -5,7 +5,7 @@
 	"copyright": "Copyright © 2025, Andrew Lalis",
 	"dependencies": {
 		"handy-http-primitives": "~>1.6",
-		"slf4d": "~>3",
+		"slf4d": "~>4",
 		"photon": "~>0.10"
 	},
 	"description": "Websocket implementation for Handy-Http.",
diff --git a/dub.selections.json b/dub.selections.json
index c4a496e..ba24159 100644
--- a/dub.selections.json
+++ b/dub.selections.json
@@ -4,7 +4,7 @@
 		"handy-http-primitives": "1.6.0",
 		"photon": "0.10.2",
 		"sharded-map": "2.7.0",
-		"slf4d": "3.0.1",
+		"slf4d": "4.0.0",
 		"streams": "3.6.0"
 	}
 }