diff --git a/src/com/google/inject/spi/Elements.java b/src/com/google/inject/spi/Elements.java
index 0b23dba..44084d7 100644
--- a/src/com/google/inject/spi/Elements.java
+++ b/src/com/google/inject/spi/Elements.java
@@ -37,6 +37,7 @@
 import com.google.inject.internal.ImmutableList;
 import com.google.inject.internal.Lists;
 import static com.google.inject.internal.Preconditions.checkArgument;
+import static com.google.inject.internal.Preconditions.checkNotNull;
 import static com.google.inject.internal.Preconditions.checkState;
 import com.google.inject.internal.PrivateElementsImpl;
 import com.google.inject.internal.ProviderMethodsModule;
@@ -181,6 +182,8 @@
     }
 
     public void install(Module module) {
+      checkNotNull(module, "module");
+
       if (modules.add(module)) {
         Binder binder = this;
         if (module instanceof PrivateModule) {