diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index f16d89593d..b3b97054fd 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -20,7 +20,7 @@ androidx-compose-material3 = "1.3.1"
 androidx-compose-runtime = "1.7.5"
 androidx-compose-ui = "1.7.5"
 androidx-constraintlayout = "2.2.0"
-androidx-core = "1.15.0"
+androidx-core = "1.13.1"
 androidx-datastore = "1.1.1"
 androidx-fragment-ktx = "1.8.5"
 androidx-legacy = "1.0.0"
@@ -55,7 +55,7 @@ kotlinx-serialization-json = "1.6.3"
 # See https://github.com/google/ksp/releases
 ksp = "1.9.24-1.0.20"
 
-ktlint = "12.1.1"
+ktlint = "11.5.1"
 
 # We cannot upgrade to 1.9.0 as it conflicts with liblcp.
 # See https://github.com/readium/kotlin-toolkit/issues/29