diff --git a/lib/facter/java_version.rb b/lib/facter/java_version.rb
index bc313df..e3ce186 100644
--- a/lib/facter/java_version.rb
+++ b/lib/facter/java_version.rb
@@ -12,12 +12,23 @@
 # Notes:
 #   None
 Facter.add(:java_version) do
+  # the OS-specific overrides need to be able to return nil,
+  # to indicate "no java available". Usually returning nil
+  # would mean that facter falls back to a lower priority
+  # resolution, which would then trigger MODULES-2637. To
+  # avoid that, we confine the "default" here to not run
+  # on those OS.
+  # Additionally, facter versions prior to 2.0.1 only support
+  # positive matches, so this needs to be done manually in setcode.
   setcode do
-    if Facter::Util::Resolution.which('java')
-      Facter::Util::Resolution.exec('java -Xmx8m -version 2>&1').lines.first.split(/"/)[1].strip
+    unless [ 'openbsd', 'darwin' ].include? Facter.value(:operatingsystem).downcase
+      if Facter::Util::Resolution.which('java')
+        Facter::Util::Resolution.exec('java -Xmx8m -version 2>&1').lines.first.split(/"/)[1].strip
+      end
     end
   end
 end
+
 Facter.add(:java_version) do
   confine :operatingsystem => 'OpenBSD'
   has_weight 100
@@ -29,3 +40,13 @@ Facter.add(:java_version) do
     end
   end
 end
+
+Facter.add(:java_version) do
+  confine :operatingsystem => 'Darwin'
+  has_weight 100
+  setcode do
+    unless /Unable to find any JVMs matching version/ =~ Facter::Util::Resolution.exec('/usr/libexec/java_home --failfast 2>&1')
+      Facter::Util::Resolution.exec('java -Xmx8m -version 2>&1').lines.first.split(/"/)[1].strip
+    end
+  end
+end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 2c6f566..145dcf5 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1 +1,6 @@
 require 'puppetlabs_spec_helper/module_spec_helper'
+
+RSpec.configure do |c|
+  # declare an exclusion filter for the tests using with_env on facter 1.6, as the function is not available on 1.6
+  c.filter_run_excluding :with_env => true if Facter.version =~ /^1\.6\./
+end
diff --git a/spec/unit/facter/java_major_version_spec.rb b/spec/unit/facter/java_major_version_spec.rb
index 94d1328..5c83081 100644
--- a/spec/unit/facter/java_major_version_spec.rb
+++ b/spec/unit/facter/java_major_version_spec.rb
@@ -11,7 +11,7 @@ describe Facter::Util::Fact do
         Facter.fact(:java_version).stubs(:value).returns('1.7.0_71')
       end
       it do
-        Facter.fact(:java_major_version).value.should == "7"
+        expect(Facter.fact(:java_major_version).value).to eq("7")
       end
     end
 
@@ -20,8 +20,8 @@ describe Facter::Util::Fact do
         Facter.fact(:java_version).stubs(:value).returns(nil)
       end
       it do
-        Facter.fact(:java_major_version).value.should be_nil
+        expect(Facter.fact(:java_major_version).value).to be_nil
       end
     end
   end
-end
\ No newline at end of file
+end
diff --git a/spec/unit/facter/java_patch_level_spec.rb b/spec/unit/facter/java_patch_level_spec.rb
index 0619831..5f99eab 100644
--- a/spec/unit/facter/java_patch_level_spec.rb
+++ b/spec/unit/facter/java_patch_level_spec.rb
@@ -12,7 +12,7 @@ describe Facter::Util::Fact do
           Facter.fact(:java_version).stubs(:value).returns('1.7.0_71')
         end
         it do
-          Facter.fact(:java_patch_level).value.should == "71"
+          expect(Facter.fact(:java_patch_level).value).to eq("71")
         end
       end
     end
@@ -23,7 +23,7 @@ describe Facter::Util::Fact do
           Facter.fact(:java_version).stubs(:value).returns(nil)
         end
         it do
-          Facter.fact(:java_patch_level).value.should be_nil
+          expect(Facter.fact(:java_patch_level).value).to be_nil
         end
       end
     end
diff --git a/spec/unit/facter/java_version_spec.rb b/spec/unit/facter/java_version_spec.rb
index c5f5ec8..7d1aa1b 100644
--- a/spec/unit/facter/java_version_spec.rb
+++ b/spec/unit/facter/java_version_spec.rb
@@ -7,7 +7,7 @@ describe Facter::Util::Fact do
 
   describe "java_version" do
     context 'returns java version when java present' do
-      context 'on OpenBSD' do
+      context 'on OpenBSD', :with_env => true do
         before do
           Facter.fact(:operatingsystem).stubs(:value).returns("OpenBSD")
         end
@@ -20,6 +20,22 @@ OpenJDK 64-Bit Server VM (build 24.71-b01, mixed mode)
           EOS
           Facter::Util::Resolution.expects(:which).with("java").returns('/usr/local/jdk-1.7.0/jre/bin/java')
           Facter::Util::Resolution.expects(:exec).with("java -Xmx8m -version 2>&1").returns(java_version_output)
+          expect(Facter.value(:java_version)).to eq("1.7.0_71")
+        end
+      end
+      context 'on Darwin' do
+        before do
+          Facter.fact(:operatingsystem).stubs(:value).returns("Darwin")
+        end
+        let(:facts) { {:operatingsystem => 'Darwin'} }
+        it do
+          java_version_output = <<-EOS
+java version "1.7.0_71"
+Java(TM) SE Runtime Environment (build 1.7.0_71-b14)
+Java HotSpot(TM) 64-Bit Server VM (build 24.71-b01, mixed mode)
+          EOS
+          Facter::Util::Resolution.expects(:exec).with("/usr/libexec/java_home --failfast 2>&1").returns("/Library/Java/JavaVirtualMachines/jdk1.7.0_71.jdk/Contents/Home")
+          Facter::Util::Resolution.expects(:exec).with("java -Xmx8m -version 2>&1").returns(java_version_output)
           Facter.value(:java_version).should == "1.7.0_71"
         end
       end
@@ -35,19 +51,29 @@ Java(TM) SE Runtime Environment (build 1.7.0_71-b14)
 Java HotSpot(TM) 64-Bit Server VM (build 24.71-b01, mixed mode)
           EOS
           Facter::Util::Resolution.expects(:exec).with("java -Xmx8m -version 2>&1").returns(java_version_output)
-          Facter.value(:java_version).should == "1.7.0_71"
+          expect(Facter.value(:java_version)).to eq("1.7.0_71")
         end
       end
     end
 
     context 'returns nil when java not present' do
-      context 'on OpenBSD' do
+      context 'on OpenBSD', :with_env => true do
         before do
           Facter.fact(:operatingsystem).stubs(:value).returns("OpenBSD")
         end
         let(:facts) { {:operatingsystem => 'OpenBSD'} }
         it do
           Facter::Util::Resolution.stubs(:exec)
+          expect(Facter.value(:java_version)).to be_nil
+        end
+      end
+      context 'on Darwin' do
+        before do
+          Facter.fact(:operatingsystem).stubs(:value).returns("Darwin")
+        end
+        let(:facts) { {:operatingsystem => 'Darwin'} }
+        it do
+          Facter::Util::Resolution.expects(:exec).at_least(1).with("/usr/libexec/java_home --failfast 2>&1").returns('Unable to find any JVMs matching version "(null)".')
           Facter.value(:java_version).should be_nil
         end
       end
@@ -58,7 +84,7 @@ Java HotSpot(TM) 64-Bit Server VM (build 24.71-b01, mixed mode)
         let(:facts) { {:operatingsystem => 'MyOS'} }
         it do
           Facter::Util::Resolution.expects(:which).at_least(1).with("java").returns(false)
-          Facter.value(:java_version).should be_nil
+          expect(Facter.value(:java_version)).to be_nil
         end
       end
     end