diff --git a/assertj-swing/src/main/java/org/assertj/swing/util/OSIdentifier.java b/assertj-swing/src/main/java/org/assertj/swing/util/OSIdentifier.java
index 7736ff4d..8e261702 100644
--- a/assertj-swing/src/main/java/org/assertj/swing/util/OSIdentifier.java
+++ b/assertj-swing/src/main/java/org/assertj/swing/util/OSIdentifier.java
@@ -34,7 +34,6 @@ class OSIdentifier {
   private final boolean isWindows;
   private final boolean isWindows9x;
   private final boolean isWindowsXP;
-  private final boolean isMacintosh;
   private final boolean isOSX;
   private final boolean isX11;
   private final boolean isSolaris;
@@ -49,12 +48,10 @@ class OSIdentifier {
   @VisibleForTesting
   OSIdentifier(@Nonnull SystemPropertyReader reader) {
     String osName = checkNotNull(reader.systemProperty("os.name")).toLowerCase(ENGLISH);
-    String mrjVersion = reader.systemProperty("mrj.version");
     isWindows = osName.startsWith("windows");
     isWindows9x = isWindows && containsAny(osName, "95", "98", "me");
     isWindowsXP = isWindows && osName.contains("xp");
-    isMacintosh = mrjVersion != null;
-    isOSX = isMacintosh && osName.contains("os x");
+    isOSX = osName.contains("os x");
     isX11 = !isOSX && !isWindows;
     isSolaris = osName.startsWith("sunos") || osName.startsWith("solaris");
     isHPUX = osName.equals("hp-ux");
@@ -98,7 +95,8 @@ boolean isWindowsXP() {
   }
 
   boolean isMacintosh() {
-    return isMacintosh;
+    // currently we assume only Mac OS X is used
+    return isOSX();
   }
 
   boolean isOSX() {
diff --git a/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_TestCase.java b/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_TestCase.java
index 2fc15940..75e44fbd 100644
--- a/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_TestCase.java
+++ b/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_TestCase.java
@@ -35,16 +35,4 @@ public void setUp() {
   final void returnOSName(String osName) {
     when(propertyReader.systemProperty("os.name")).thenReturn(osName);
   }
-
-  final void returnSomeMRJVersion() {
-    returnMRJVersion("6");
-  }
-
-  final void returnNoMRJVersion() {
-    returnMRJVersion(null);
-  }
-
-  final void returnMRJVersion(String mrjVersion) {
-    when(propertyReader.systemProperty("mrj.version")).thenReturn(mrjVersion);
-  }
 }
diff --git a/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isHPUX_Test.java b/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isHPUX_Test.java
index 7e5ab87e..6bc948e0 100644
--- a/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isHPUX_Test.java
+++ b/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isHPUX_Test.java
@@ -46,7 +46,6 @@ public OSIdentifier_isHPUX_Test(String hpUX) {
   @Test
   public void should_return_HPUX_if_OS_name_is_equal_to_HPUX() {
     returnOSName(hpUX);
-    returnNoMRJVersion();
     OSIdentifier osIdentifier = new OSIdentifier(propertyReader);
     assertThat(osIdentifier.isHPUX()).isTrue();
     assertThat(osIdentifier.isX11()).isTrue();
diff --git a/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isLinux_Test.java b/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isLinux_Test.java
index 41c11dfe..9ca3c02d 100644
--- a/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isLinux_Test.java
+++ b/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isLinux_Test.java
@@ -46,7 +46,6 @@ public OSIdentifier_isLinux_Test(String linux) {
   @Test
   public void shouldReturnLinuxIfOSNameIsEqualToLinux() {
     returnOSName(linux);
-    returnNoMRJVersion();
     OSIdentifier osIdentifier = new OSIdentifier(propertyReader);
     assertThat(osIdentifier.isLinux()).isTrue();
     assertThat(osIdentifier.isX11()).isTrue();
diff --git a/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isMacintosh_Test.java b/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isMacintosh_Test.java
index 2b2c78c6..d7475a4f 100644
--- a/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isMacintosh_Test.java
+++ b/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isMacintosh_Test.java
@@ -15,30 +15,47 @@
 package org.assertj.swing.util;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.util.Lists.newArrayList;
 import static org.assertj.swing.util.OSFamily.MAC;
 
+import java.util.Collection;
+
 import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameters;
 
 /**
  * Tests for {@link OSIdentifier#isMacintosh()}.
  * 
  * @author Alex Ruiz
  */
+@RunWith(Parameterized.class)
 public class OSIdentifier_isMacintosh_Test extends OSIdentifier_TestCase {
+  private final String osX;
+
+  @Parameters
+  public static Collection<Object[]> osX() {
+    return newArrayList(new Object[][] { { "os x" }, { "OS X" } });
+  }
+
+  public OSIdentifier_isMacintosh_Test(String osX) {
+    this.osX = osX;
+  }
+
   @Test
-  public void should_return_Macintosh_if_MRJVersion_is_not_null() {
-    returnOSName("");
-    returnSomeMRJVersion();
+  public void should_return_OSX_if_OS_name_contains_OSX_even_if_mrj_version_is_Null() {
+    returnOSName(osX);
     OSIdentifier osIdentifier = new OSIdentifier(propertyReader);
     assertThat(osIdentifier.isMacintosh()).isTrue();
-    assertThat(osIdentifier.isX11()).isTrue();
+    assertThat(osIdentifier.isOSX()).isTrue();
     assertThat(osIdentifier.isHPUX()).isFalse();
     assertThat(osIdentifier.isLinux()).isFalse();
-    assertThat(osIdentifier.isOSX()).isFalse();
     assertThat(osIdentifier.isSolaris()).isFalse();
     assertThat(osIdentifier.isWindows()).isFalse();
     assertThat(osIdentifier.isWindows9x()).isFalse();
     assertThat(osIdentifier.isWindowsXP()).isFalse();
+    assertThat(osIdentifier.isX11()).isFalse();
     assertThat(osIdentifier.osFamily()).isEqualTo(MAC);
   }
 }
diff --git a/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isOSX_Test.java b/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isOSX_Test.java
index f082d11f..b9a9aa91 100644
--- a/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isOSX_Test.java
+++ b/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isOSX_Test.java
@@ -46,7 +46,6 @@ public OSIdentifier_isOSX_Test(String osX) {
   @Test
   public void should_return_OSX_if_MRJVersion_not_null_and_OS_name_contains_OSX() {
     returnOSName(osX);
-    returnSomeMRJVersion();
     OSIdentifier osIdentifier = new OSIdentifier(propertyReader);
     assertThat(osIdentifier.isMacintosh()).isTrue();
     assertThat(osIdentifier.isOSX()).isTrue();
diff --git a/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isSolaris_Test.java b/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isSolaris_Test.java
index d88ba811..e8e0a33b 100644
--- a/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isSolaris_Test.java
+++ b/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isSolaris_Test.java
@@ -47,7 +47,6 @@ public OSIdentifier_isSolaris_Test(String solaris) {
   @Test
   public void should_return_Solaris_if_OS_name_starts_with_SunOS_or_Solaris() {
     returnOSName(solaris);
-    returnNoMRJVersion();
     OSIdentifier osIdentifier = new OSIdentifier(propertyReader);
     assertThat(osIdentifier.isSolaris()).isTrue();
     assertThat(osIdentifier.isX11()).isTrue();
diff --git a/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isWindows9x_Test.java b/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isWindows9x_Test.java
index 33217a09..3462ceeb 100644
--- a/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isWindows9x_Test.java
+++ b/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isWindows9x_Test.java
@@ -46,7 +46,6 @@ public OSIdentifier_isWindows9x_Test(String windows9x) {
   @Test
   public void should_return_is_Windows9x_if_OS_name_starts_with_Windows_and_contains_any_9x_version() {
     returnOSName(windows9x);
-    returnNoMRJVersion();
     OSIdentifier osIdentifier = new OSIdentifier(propertyReader);
     assertThat(osIdentifier.isWindows()).isTrue();
     assertThat(osIdentifier.isWindows9x()).isTrue();
diff --git a/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isWindowsXP_Test.java b/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isWindowsXP_Test.java
index 51a52ad8..51ff4371 100644
--- a/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isWindowsXP_Test.java
+++ b/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isWindowsXP_Test.java
@@ -46,7 +46,6 @@ public OSIdentifier_isWindowsXP_Test(String windowsXP) {
   @Test
   public void should_return_WindowsXP_if_OS_name_starts_with_Windows_and_contains_XP() {
     returnOSName(windowsXP);
-    returnNoMRJVersion();
     OSIdentifier osIdentifier = new OSIdentifier(propertyReader);
     assertThat(osIdentifier.isWindows()).isTrue();
     assertThat(osIdentifier.isWindowsXP()).isTrue();
diff --git a/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isWindows_Test.java b/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isWindows_Test.java
index 52368b1f..9ab845d8 100644
--- a/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isWindows_Test.java
+++ b/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isWindows_Test.java
@@ -46,7 +46,6 @@ public OSIdentifier_isWindows_Test(String windows) {
   @Test
   public void should_return_is_Windows_if_OS_name_starts_with_Windows() {
     returnOSName(windows);
-    returnNoMRJVersion();
     OSIdentifier osIdentifier = new OSIdentifier(propertyReader);
     assertThat(osIdentifier.isWindows()).isTrue();
     assertThat(osIdentifier.isHPUX()).isFalse();
diff --git a/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isX11_Test.java b/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isX11_Test.java
index 2ec419b2..5f1e724b 100644
--- a/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isX11_Test.java
+++ b/assertj-swing/src/test/java/org/assertj/swing/util/OSIdentifier_isX11_Test.java
@@ -27,7 +27,6 @@ public class OSIdentifier_isX11_Test extends OSIdentifier_TestCase {
   @Test
   public void should_return_X11_if_OS_not_OSX_or_Windows() {
     returnOSName("");
-    returnNoMRJVersion();
     OSIdentifier osIdentifier = new OSIdentifier(propertyReader);
     assertThat(osIdentifier.isX11()).isTrue();
     assertThat(osIdentifier.isHPUX()).isFalse();