diff --git a/src/com/google/inject/internal/Types.java b/src/com/google/inject/internal/Types.java
index 41f593d..e0d6af7 100644
--- a/src/com/google/inject/internal/Types.java
+++ b/src/com/google/inject/internal/Types.java
@@ -239,6 +239,11 @@
       this.rawType = canonicalize(rawType);
       this.typeArguments = typeArguments.clone();
       for (int t = 0; t < this.typeArguments.length; t++) {
+        if (this.typeArguments[t] instanceof Class<?> 
+            && ((Class) this.typeArguments[t]).isPrimitive()) {
+          throw new IllegalArgumentException(
+              "Parameterized types may not have primitive arguments: " + this.typeArguments[t]);
+        }
         this.typeArguments[t] = canonicalize(this.typeArguments[t]);
       }
     }
diff --git a/test/com/google/inject/OptionalBindingTest.java b/test/com/google/inject/OptionalBindingTest.java
index 76d4bae..a8973fd 100644
--- a/test/com/google/inject/OptionalBindingTest.java
+++ b/test/com/google/inject/OptionalBindingTest.java
@@ -269,6 +269,20 @@
     assertSame(staticInjectA, injectA);
   }
 
+  /**
+   * Test for bug 107, where we weren't doing optional injection properly for
+   * indirect injections.
+   */
+  public void testIndirectOptionalInjection() {
+    Indirect indirect = Guice.createInjector().getInstance(Indirect.class);
+    assertNotNull(indirect.hasOptionalInjections);
+    indirect.hasOptionalInjections.assertNothingInjected();
+  }
+
+  static class Indirect {
+    @Inject HasOptionalInjections hasOptionalInjections;
+  }
+
   interface A {}
   interface B {}
   interface C {}
diff --git a/test/com/google/inject/ScopesTest.java b/test/com/google/inject/ScopesTest.java
index 46313ae..064434e 100644
--- a/test/com/google/inject/ScopesTest.java
+++ b/test/com/google/inject/ScopesTest.java
@@ -64,7 +64,6 @@
         injector.getInstance(LinkedSingleton.class),
         injector.getInstance(LinkedSingleton.class));
 
-
     assertSame(
         injector.getInstance(JustInTimeSingleton.class),
         injector.getInstance(JustInTimeSingleton.class));
diff --git a/test/com/google/inject/internal/TypesTest.java b/test/com/google/inject/internal/TypesTest.java
index 2e53a2e..3d89809 100644
--- a/test/com/google/inject/internal/TypesTest.java
+++ b/test/com/google/inject/internal/TypesTest.java
@@ -18,6 +18,7 @@
 package com.google.inject.internal;
 
 import static com.google.inject.Asserts.assertEqualsBothWays;
+import com.google.inject.Asserts;
 import junit.framework.TestCase;
 
 import java.lang.reflect.GenericArrayType;
@@ -66,6 +67,16 @@
     assertEquals(innerFloatDouble.toString(), actual.toString());
   }
 
+  public void testTypeParametersMustNotBePrimitives() {
+    try {
+      Types.newTypeWithArgument(Map.class, String.class, int.class);
+      fail();
+    } catch (IllegalArgumentException expected) {
+      Asserts.assertContains(expected.getMessage(),
+          "Parameterized types may not have primitive arguments: int");
+    }
+  }
+
   public void testEqualsAndHashcode() {
     ParameterizedType parameterizedType
         = Types.newTypeWithArgument(Map.class, String.class, Integer.class);
@@ -89,5 +100,6 @@
         Types.toString(innerFloatDouble));
   }
 
+  @SuppressWarnings("UnusedDeclaration")
   class Inner<T1, T2> {}
 }