diff --git a/ext/cbson/cbson.c b/ext/cbson/cbson.c
index 8509ee2..f8fe2e5 100644
--- a/ext/cbson/cbson.c
+++ b/ext/cbson/cbson.c
@@ -49,6 +49,7 @@ static VALUE DBRef;
 static VALUE Code;
 static VALUE RegexpOfHolding;
 static VALUE OrderedHash;
+static VALUE InvalidName;
 
 // this sucks. but for some reason these moved around between 1.8 and 1.9
 #ifdef ONIGURUMA_H
@@ -183,11 +184,11 @@ static int write_element_allow_id(VALUE key, VALUE value, VALUE extra, int allow
     if (check_keys == Qtrue) {
         int i;
         if (RSTRING_LEN(key) > 0 && RSTRING_PTR(key)[0] == '$') {
-            rb_raise(rb_eRuntimeError, "key must not start with '$'");
+            rb_raise(InvalidName, "key must not start with '$'");
         }
         for (i = 0; i < RSTRING_LEN(key); i++) {
             if (RSTRING_PTR(key)[i] == '.') {
-                rb_raise(rb_eRuntimeError, "key must not contain '.'");
+                rb_raise(InvalidName, "key must not contain '.'");
             }
         }
     }
@@ -755,6 +756,8 @@ void Init_cbson() {
     Code = rb_const_get(driver, rb_intern("Code"));
     rb_require("mongo/types/regexp_of_holding");
     RegexpOfHolding = rb_const_get(driver, rb_intern("RegexpOfHolding"));
+    rb_require("mongo/errors");
+    InvalidName = rb_const_get(driver, rb_intern("InvalidName"));
     rb_require("mongo/util/ordered_hash");
     OrderedHash = rb_const_get(rb_cObject, rb_intern("OrderedHash"));
 
diff --git a/lib/mongo/collection.rb b/lib/mongo/collection.rb
index 6a15aa3..cedce42 100644
--- a/lib/mongo/collection.rb
+++ b/lib/mongo/collection.rb
@@ -29,19 +29,19 @@ module XGen
           case name
           when Symbol, String
           else
-            raise RuntimeError, "new_name must be a string or symbol"
+            raise TypeError, "new_name must be a string or symbol"
           end
 
           name = name.to_s
 
           if name.empty? or name.include? ".."
-            raise RuntimeError, "collection names cannot be empty"
+            raise InvalidName, "collection names cannot be empty"
           end
           if name.include? "$" and not name.match(/^\$cmd/)
-            raise RuntimeError, "collection names must not contain '$'"
+            raise InvalidName, "collection names must not contain '$'"
           end
           if name.match(/^\./) or name.match(/\.$/)
-            raise RuntimeError, "collection names must not start or end with '.'"
+            raise InvalidName, "collection names must not start or end with '.'"
           end
 
           @db, @name = db, name
@@ -256,7 +256,7 @@ EOS
         # Rename this collection.
         #
         # If operating in auth mode, client must be authorized as an admin to
-        # perform this operation. Raises an error if +new_name+ is an invalid
+        # perform this operation. Raises +InvalidName+ if +new_name+ is an invalid
         # collection name.
         #
         # :new_name :: new name for this collection
@@ -264,19 +264,19 @@ EOS
           case new_name
           when Symbol, String
           else
-            raise RuntimeError, "new_name must be a string or symbol"
+            raise TypeError, "new_name must be a string or symbol"
           end
 
           new_name = new_name.to_s
 
           if new_name.empty? or new_name.include? ".."
-            raise RuntimeError, "collection names cannot be empty"
+            raise InvalidName, "collection names cannot be empty"
           end
           if new_name.include? "$"
-            raise RuntimeError, "collection names must not contain '$'"
+            raise InvalidName, "collection names must not contain '$'"
           end
           if new_name.match(/^\./) or new_name.match(/\.$/)
-            raise RuntimeError, "collection names must not start or end with '.'"
+            raise InvalidName, "collection names must not start or end with '.'"
           end
 
           @db.rename_collection(@name, new_name)
diff --git a/lib/mongo/errors.rb b/lib/mongo/errors.rb
index 3847ea3..d2b881a 100644
--- a/lib/mongo/errors.rb
+++ b/lib/mongo/errors.rb
@@ -19,6 +19,9 @@ module XGen
     module Driver
       # Raised when a database operation fails.
       class OperationFailure < RuntimeError; end
+
+      # Raised when an invalid name is used.
+      class InvalidName < RuntimeError; end
     end
   end
 end
diff --git a/lib/mongo/util/bson.rb b/lib/mongo/util/bson.rb
index a7afaa0..487e7c3 100644
--- a/lib/mongo/util/bson.rb
+++ b/lib/mongo/util/bson.rb
@@ -104,10 +104,10 @@ class BSON
     k = k.to_s
     if check_keys
       if k[0] == ?$
-        raise RuntimeError.new("key #{k} must not start with '$'")
+        raise InvalidName.new("key #{k} must not start with '$'")
       end
       if k.include? ?.
-        raise RuntimeError.new("key #{k} must not contain '.'")
+        raise InvalidName.new("key #{k} must not contain '.'")
       end
     end
     type = bson_type(v)
diff --git a/tests/test_db_api.rb b/tests/test_db_api.rb
index 7d4eaae..8f0e197 100644
--- a/tests/test_db_api.rb
+++ b/tests/test_db_api.rb
@@ -690,32 +690,32 @@ class DBAPITest < Test::Unit::TestCase
     @@coll.insert({"hello" => "world"})
     @@coll.insert({"hello" => {"hello" => "world"}})
 
-    assert_raise RuntimeError do
+    assert_raise InvalidName do
       @@coll.insert({"$hello" => "world"})
     end
-    assert_raise RuntimeError do
+    assert_raise InvalidName do
       @@coll.insert({"hello" => {"$hello" => "world"}})
     end
 
     @@coll.insert({"he$llo" => "world"})
     @@coll.insert({"hello" => {"hell$o" => "world"}})
 
-    assert_raise RuntimeError do
+    assert_raise InvalidName do
       @@coll.insert({".hello" => "world"})
     end
-    assert_raise RuntimeError do
+    assert_raise InvalidName do
       @@coll.insert({"hello" => {".hello" => "world"}})
     end
-    assert_raise RuntimeError do
+    assert_raise InvalidName do
       @@coll.insert({"hello." => "world"})
     end
-    assert_raise RuntimeError do
+    assert_raise InvalidName do
       @@coll.insert({"hello" => {"hello." => "world"}})
     end
-    assert_raise RuntimeError do
+    assert_raise InvalidName do
       @@coll.insert({"hel.lo" => "world"})
     end
-    assert_raise RuntimeError do
+    assert_raise InvalidName do
       @@coll.insert({"hello" => {"hel.lo" => "world"}})
     end
 
@@ -723,22 +723,22 @@ class DBAPITest < Test::Unit::TestCase
   end
 
   def test_collection_names
-    assert_raise RuntimeError do
+    assert_raise TypeError do
       @@db.collection(5)
     end
-    assert_raise RuntimeError do
+    assert_raise InvalidName do
       @@db.collection("")
     end
-    assert_raise RuntimeError do
+    assert_raise InvalidName do
       @@db.collection("te$t")
     end
-    assert_raise RuntimeError do
+    assert_raise InvalidName do
       @@db.collection(".test")
     end
-    assert_raise RuntimeError do
+    assert_raise InvalidName do
       @@db.collection("test.")
     end
-    assert_raise RuntimeError do
+    assert_raise InvalidName do
       @@db.collection("tes..t")
     end
   end
@@ -749,22 +749,22 @@ class DBAPITest < Test::Unit::TestCase
     a = @@db.collection("foo")
     b = @@db.collection("bar")
 
-    assert_raise RuntimeError do
+    assert_raise TypeError do
       a.rename(5)
     end
-    assert_raise RuntimeError do
+    assert_raise InvalidName do
       a.rename("")
     end
-    assert_raise RuntimeError do
+    assert_raise InvalidName do
       a.rename("te$t")
     end
-    assert_raise RuntimeError do
+    assert_raise InvalidName do
       a.rename(".test")
     end
-    assert_raise RuntimeError do
+    assert_raise InvalidName do
       a.rename("test.")
     end
-    assert_raise RuntimeError do
+    assert_raise InvalidName do
       a.rename("tes..t")
     end