diff --git a/Package.resolved b/Package.resolved
index e934a06e..6e937c02 100644
--- a/Package.resolved
+++ b/Package.resolved
@@ -105,8 +105,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/apple/swift-collections.git",
       "state" : {
-        "revision" : "a0cb0954ecb21e4e31b0070e6ed5674e8556685a",
-        "version" : "1.6.0"
+        "revision" : "fea17c02d767f46b23070fdfdacc28a03a39232a",
+        "version" : "1.5.1"
       }
     },
     {