diff --git a/build/org.eclipse.cdt.managedbuilder.core.tests/tests/org/eclipse/cdt/managedbuilder/language/settings/providers/tests/GCCBuildCommandParserTest.java b/build/org.eclipse.cdt.managedbuilder.core.tests/tests/org/eclipse/cdt/managedbuilder/language/settings/providers/tests/GCCBuildCommandParserTest.java
index 73b3fe9ea05..6182e47d852 100644
--- a/build/org.eclipse.cdt.managedbuilder.core.tests/tests/org/eclipse/cdt/managedbuilder/language/settings/providers/tests/GCCBuildCommandParserTest.java
+++ b/build/org.eclipse.cdt.managedbuilder.core.tests/tests/org/eclipse/cdt/managedbuilder/language/settings/providers/tests/GCCBuildCommandParserTest.java
@@ -688,7 +688,7 @@ public class GCCBuildCommandParserTest extends BaseTestCase {
 
 		// check populated entries
 		List<ICLanguageSettingEntry> entries = parser.getSettingEntries(cfgDescription, file, languageId);
-		CMacroEntry expected = new CMacroEntry("MACRO0", "", 0);
+		CMacroEntry expected = new CMacroEntry("MACRO0", "1", 0);
 		CMacroEntry entry = (CMacroEntry)entries.get(0);
 		assertEquals(expected.getName(), entry.getName());
 		assertEquals(expected.getValue(), entry.getValue());
@@ -1979,8 +1979,8 @@ public class GCCBuildCommandParserTest extends BaseTestCase {
 		assertFalse(new java.io.File("/Python1025/Include").exists());
 		assertEquals(new CIncludePathEntry("/Python1025/Include", 0), entries.get(1));
 		assertEquals(new CMacroEntry("BOOST_ALL_NO_LIB", "1", 0), entries.get(2));
-		assertEquals(new CMacroEntry("BOOST_PYTHON_SOURCE", "", 0), entries.get(3));
-		assertEquals(new CMacroEntry("BOOST_PYTHON_STATIC_LIB", "", 0), entries.get(4));
+		assertEquals(new CMacroEntry("BOOST_PYTHON_SOURCE", "1", 0), entries.get(3));
+		assertEquals(new CMacroEntry("BOOST_PYTHON_STATIC_LIB", "1", 0), entries.get(4));
 		assertEquals(5, entries.size());
 	}
 
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/language/settings/providers/GCCBuildCommandParser.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/language/settings/providers/GCCBuildCommandParser.java
index 87967cbd07f..939d5a19e6a 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/language/settings/providers/GCCBuildCommandParser.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/language/settings/providers/GCCBuildCommandParser.java
@@ -43,7 +43,8 @@ public class GCCBuildCommandParser extends AbstractBuildCommandParser implements
 			new MacroOptionParser("-D\\s*([^\\s=\"']*)=(\"\\\\(\")(.*?)\\\\\"\")", "$1", "$3$4$3"),
 			new MacroOptionParser("-D\\s*([^\\s=\"']*)=(\\\\([\"']))(.*?)\\2", "$1", "$3$4$3"),
 			new MacroOptionParser("-D\\s*([^\\s=\"']*)=([\"'])(.*?)\\2", "$1", "$3"),
-			new MacroOptionParser("-D\\s*([^\\s=\"']*)(=([^\\s\"']*))?", "$1", "$3"),
+			new MacroOptionParser("-D\\s*([^\\s=\"']*)=([^\\s\"']*)?", "$1", "$2"),
+			new MacroOptionParser("-D\\s*([^\\s=\"']*)", "$1", "1"),
 			new MacroOptionParser("-U\\s*([^\\s=\"']*)", "$1", ICSettingEntry.UNDEFINED),
 			new MacroFileOptionParser("-imacros\\s*([\"'])(.*)\\1", "$2"),
 			new MacroFileOptionParser("-imacros\\s*([^\\s\"']*)", "$1"),