diff --git a/app/src/main/java/com/wireguard/config/Config.java b/app/src/main/java/com/wireguard/config/Config.java
index 6c9d7ba3..7b9bcab3 100644
--- a/app/src/main/java/com/wireguard/config/Config.java
+++ b/app/src/main/java/com/wireguard/config/Config.java
@@ -30,7 +30,9 @@ public final class Config {
     private final List<Peer> peers;
 
     private Config(final Builder builder) {
-        interfaze = Objects.requireNonNull(builder.interfaze, "An [Interface] section is required");
+        if (builder.interfaze == null)
+            throw new IllegalArgumentException("An [Interface] section is required");
+        interfaze = builder.interfaze;
         // Defensively copy to ensure immutability even if the Builder is reused.
         peers = Collections.unmodifiableList(new ArrayList<>(builder.peers));
     }
diff --git a/app/src/main/java/com/wireguard/config/Interface.java b/app/src/main/java/com/wireguard/config/Interface.java
index 7b114a09..f97c4731 100644
--- a/app/src/main/java/com/wireguard/config/Interface.java
+++ b/app/src/main/java/com/wireguard/config/Interface.java
@@ -44,11 +44,14 @@ public final class Interface {
     private final Optional<Integer> mtu;
 
     private Interface(final Builder builder) {
+        if (builder.keyPair == null)
+            throw new IllegalArgumentException("Interfaces must have a private key");
+
         // Defensively copy to ensure immutability even if the Builder is reused.
         addresses = Collections.unmodifiableSet(new LinkedHashSet<>(builder.addresses));
         dnsServers = Collections.unmodifiableSet(new LinkedHashSet<>(builder.dnsServers));
         excludedApplications = Collections.unmodifiableSet(new LinkedHashSet<>(builder.excludedApplications));
-        keyPair = Objects.requireNonNull(builder.keyPair, "Interfaces must have a private key");
+        keyPair = builder.keyPair;
         listenPort = builder.listenPort;
         mtu = builder.mtu;
     }
diff --git a/app/src/main/java/com/wireguard/config/Peer.java b/app/src/main/java/com/wireguard/config/Peer.java
index c15d3ae9..1eb30197 100644
--- a/app/src/main/java/com/wireguard/config/Peer.java
+++ b/app/src/main/java/com/wireguard/config/Peer.java
@@ -35,12 +35,14 @@ public final class Peer {
     private final Key publicKey;
 
     private Peer(final Builder builder) {
+        if (builder.publicKey == null)
+            throw new IllegalArgumentException("Peers must have a public key");
         // Defensively copy to ensure immutability even if the Builder is reused.
         allowedIps = Collections.unmodifiableSet(new LinkedHashSet<>(builder.allowedIps));
         endpoint = builder.endpoint;
         persistentKeepalive = builder.persistentKeepalive;
         preSharedKey = builder.preSharedKey;
-        publicKey = Objects.requireNonNull(builder.publicKey, "Peers must have a public key");
+        publicKey = builder.publicKey;
     }
 
     /**