diff --git a/app/build.gradle b/app/build.gradle
index 21f96ba..6f2d0e4 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -41,5 +41,5 @@ dependencies {
     // ZXing QR decoder deps
     implementation 'com.google.zxing:core:3.5.0'
 
-    implementation 'org.bouncycastle:bcprov-jdk15to18:1.78'
+    implementation 'org.bouncycastle:bcprov-jdk18on:1.85'
 }
diff --git a/guardian/build.gradle b/guardian/build.gradle
index 72f5af2..da3c23f 100644
--- a/guardian/build.gradle
+++ b/guardian/build.gradle
@@ -78,6 +78,10 @@ mavenPublishing {
     }
 }
 
+configurations.all {
+    resolutionStrategy.force 'org.bouncycastle:bcprov-jdk18on:1.85'
+}
+
 dependencies {
     // Annotations (@NonNull etc)
     implementation 'androidx.annotation:annotation:1.9.1'