diff --git a/lib/mongo/connection.rb b/lib/mongo/connection.rb
index 094f996..a7aa60e 100644
--- a/lib/mongo/connection.rb
+++ b/lib/mongo/connection.rb
@@ -430,7 +430,13 @@ module Mongo
       reset_connection
 
       config = check_is_master(@host_to_try)
-      if is_primary?(config)
+      if config
+        if config['ismaster'] == 1 || config['ismaster'] == true
+          @read_primary = true
+        elsif @slave_ok
+          @read_primary = false
+        end
+
         set_primary(@host_to_try)
       end
 
@@ -450,6 +456,14 @@ module Mongo
       @primary_pool && @primary_pool.host && @primary_pool.port
     end
 
+    # Determine whether we're reading from a primary node. If false,
+    # this connection connects to a secondary node and @slave_ok is true.
+    #
+    # @return [Boolean]
+    def read_primary?
+      @read_primary
+    end
+
     # Close the connection to the database.
     def close
       @primary_pool.close if @primary_pool
@@ -552,16 +566,6 @@ module Mongo
       @primary = nil
     end
 
-    # Primary is defined as either a master node or a slave if
-    # :slave_ok has been set to +true+.
-    #
-    # If a primary node is discovered, we set the the @host and @port and
-    # apply any saved authentication.
-    # TODO: simplify
-    def is_primary?(config)
-      config && (config['ismaster'] == 1 || config['ismaster'] == true) || @slave_ok
-    end
-
     def check_is_master(node)
       begin
         host, port = *node
diff --git a/lib/mongo/repl_set_connection.rb b/lib/mongo/repl_set_connection.rb
index f90d593..ecc5292 100644
--- a/lib/mongo/repl_set_connection.rb
+++ b/lib/mongo/repl_set_connection.rb
@@ -124,6 +124,14 @@ module Mongo
       @nodes_to_try.length > 0
     end
 
+    # Determine whether we're reading from a primary node. If false,
+    # this connection connects to a secondary node and @read_secondaries is true.
+    #
+    # @return [Boolean]
+    def read_primary?
+      !@read_pool || @read_pool.length.zero?
+    end
+
     # Close the connection to the database.
     def close
       super
diff --git a/test/replica_sets/connect_test.rb b/test/replica_sets/connect_test.rb
index 03bd0ba..3b018f7 100644
--- a/test/replica_sets/connect_test.rb
+++ b/test/replica_sets/connect_test.rb
@@ -31,6 +31,7 @@ class ConnectTest < Test::Unit::TestCase
     @conn = ReplSetConnection.new([RS.host, RS.ports[0]], [RS.host, RS.ports[1]],
       [RS.host, RS.ports[2]], :name => RS.name)
     assert @conn.connected?
+    assert @conn.read_primary?
 
     assert_equal RS.primary, @conn.primary
     assert_equal RS.secondaries.sort, @conn.secondaries.sort
diff --git a/test/replica_sets/query_secondaries.rb b/test/replica_sets/query_secondaries.rb
index c4a28f6..fe1770e 100644
--- a/test/replica_sets/query_secondaries.rb
+++ b/test/replica_sets/query_secondaries.rb
@@ -16,6 +16,10 @@ class ReplicaSetQuerySecondariesTest < Test::Unit::TestCase
     RS.restart_killed_nodes
   end
 
+  def test_read_primary
+    assert !@conn.read_primary?
+  end
+
   def test_con
     assert @conn.primary_pool, "No primary pool!"
     assert @conn.read_pool, "No read pool!"
diff --git a/test/replica_sets/replication_ack_test.rb b/test/replica_sets/replication_ack_test.rb
index 53441fd..33f0bb8 100644
--- a/test/replica_sets/replication_ack_test.rb
+++ b/test/replica_sets/replication_ack_test.rb
@@ -13,6 +13,8 @@ class ReplicaSetAckTest < Test::Unit::TestCase
     @slave1 = Connection.new(@conn.secondary_pools[0].host,
       @conn.secondary_pools[0].port, :slave_ok => true)
 
+    assert !@slave1.read_primary?
+
     @db = @conn.db(MONGO_TEST_DB)
     @db.drop_collection("test-sets")
     @col = @db.collection("test-sets")