diff --git a/lib/ohai/plugins/network_listeners.rb b/lib/ohai/plugins/network_listeners.rb
index 7ecfef72e..62661c773 100644
--- a/lib/ohai/plugins/network_listeners.rb
+++ b/lib/ohai/plugins/network_listeners.rb
@@ -22,35 +22,39 @@
   depends "network", "counters/network"
 
   collect_data do
-    require "sigar"
-    flags = Sigar::NETCONN_TCP | Sigar::NETCONN_SERVER
+    begin
+      require 'sigar'
+      flags = Sigar::NETCONN_TCP | Sigar::NETCONN_SERVER
 
-    network Mash.new unless network
-    listeners = Mash.new
+      network Mash.new unless network
+      listeners = Mash.new
 
-    sigar = Sigar.new
-    sigar.net_connection_list(flags).each do |conn|
-      port = conn.local_port
-      addr = conn.local_address.to_s
-      if addr == "0.0.0.0" || addr == "::"
-        addr = "*"
+      sigar = Sigar.new
+      sigar.net_connection_list(flags).each do |conn|
+        port = conn.local_port
+        addr = conn.local_address.to_s
+        if addr == "0.0.0.0" || addr == "::"
+          addr = "*"
+        end
+        listeners[port] = Mash.new
+        listeners[port][:address] = addr
+        begin
+          pid = sigar.proc_port(conn.type, port)
+          # workaround for a failure of proc_state to throw
+          # after the first 0 has been supplied to it
+          #
+          # no longer required when hyperic/sigar#48 is fixed
+          throw ArgumentError.new("No such process") if pid == 0
+          listeners[port][:pid] = pid
+          listeners[port][:name] = sigar.proc_state(pid).name
+        rescue
+        end
       end
-      listeners[port] = Mash.new
-      listeners[port][:address] = addr
-      begin
-        pid = sigar.proc_port(conn.type, port)
-        # workaround for a failure of proc_state to throw
-        # after the first 0 has been supplied to it
-        #
-        # no longer required when hyperic/sigar#48 is fixed
-        throw ArgumentError.new("No such process") if pid == 0
-        listeners[port][:pid] = pid
-        listeners[port][:name] = sigar.proc_state(pid).name
-      rescue
-      end
-    end
 
-    network[:listeners] = Mash.new
-    network[:listeners][:tcp] = listeners
+      network[:listeners] = Mash.new
+      network[:listeners][:tcp] = listeners
+    rescue LoadError
+      Ohai::Log.debug('Could not load sigar gem. Skipping NetworkListeners plugin')
+    end
   end
 end
diff --git a/lib/ohai/plugins/sigar/network_route.rb b/lib/ohai/plugins/sigar/network_route.rb
index eaed40528..f4d3161fa 100644
--- a/lib/ohai/plugins/sigar/network_route.rb
+++ b/lib/ohai/plugins/sigar/network_route.rb
@@ -19,41 +19,46 @@
 require "ohai/mixin/network_constants"
 
 Ohai.plugin(:NetworkRoutes) do
-  include Ohai::Mixin::NetworkConstants
+  begin
+    require "sigar"
 
-  provides "network/interfaces/adapters/route"
-  depends "network/interfaces"
+    include Ohai::Mixin::NetworkConstants
 
-  def flags(flags)
-    f = ""
-    if (flags & Sigar::RTF_UP) != 0
-      f += "U"
-    end
-    if (flags & Sigar::RTF_GATEWAY) != 0
-      f += "G"
-    end
-    if (flags & Sigar::RTF_HOST) != 0
-      f += "H"
+    provides "network/interfaces/adapters/route"
+    depends "network/interfaces"
+
+    def flags(flags)
+      f = ""
+      if (flags & Sigar::RTF_UP) != 0
+        f += "U"
+      end
+      if (flags & Sigar::RTF_GATEWAY) != 0
+        f += "G"
+      end
+      if (flags & Sigar::RTF_HOST) != 0
+        f += "H"
+      end
+      f
     end
-    f
-  end
 
-  collect_data(:default) do
-    require "sigar"
-    sigar = Sigar.new
+    collect_data(:default) do
+      sigar = Sigar.new
 
-    sigar.net_route_list.each do |route|
-      next unless network[:interfaces][route.ifname] # this should never happen
-      network[:interfaces][route.ifname][:route] = Mash.new unless network[:interfaces][route.ifname][:route]
-      route_data = {}
-      Ohai::Mixin::NetworkConstants::SIGAR_ROUTE_METHODS.each do |m|
-        if(m == :flags)
-          route_data[m] = flags(route.send(m))
-        else
-          route_data[m] = route.send(m)
+      sigar.net_route_list.each do |route|
+        next unless network[:interfaces][route.ifname] # this should never happen
+        network[:interfaces][route.ifname][:route] = Mash.new unless network[:interfaces][route.ifname][:route]
+        route_data = {}
+        Ohai::Mixin::NetworkConstants::SIGAR_ROUTE_METHODS.each do |m|
+          if(m == :flags)
+            route_data[m] = flags(route.send(m))
+          else
+            route_data[m] = route.send(m)
+          end
         end
+        network[:interfaces][route.ifname][:route][route.destination] = route_data
       end
-      network[:interfaces][route.ifname][:route][route.destination] = route_data
     end
+  rescue LoadError
+    Ohai::Log.debug('Could not load sigar gem. Skipping NetworkRoutes plugin')
   end
 end