diff --git a/jsoncdb/org.eclipse.cdt.jsoncdb.core.tests/src/org/eclipse/cdt/jsoncdb/core/internal/MacroDefine_C_POSIXTest.java b/jsoncdb/org.eclipse.cdt.jsoncdb.core.tests/src/org/eclipse/cdt/jsoncdb/core/internal/MacroDefine_C_POSIXTest.java
index 6f373b8887d..25e4432b6c1 100644
--- a/jsoncdb/org.eclipse.cdt.jsoncdb.core.tests/src/org/eclipse/cdt/jsoncdb/core/internal/MacroDefine_C_POSIXTest.java
+++ b/jsoncdb/org.eclipse.cdt.jsoncdb.core.tests/src/org/eclipse/cdt/jsoncdb/core/internal/MacroDefine_C_POSIXTest.java
@@ -39,7 +39,7 @@ public class MacroDefine_C_POSIXTest {
 	 * Test method for {@link Arglets.MacroDefine_C_POSIX#processArgument}.
 	 */
 	@Test
-	public final void testProcessArgument() {
+	public final void testProcessArgument_NoValue() {
 		final String more = " -g -MMD -MT CMakeFiles/execut1.dir/util1.c.o -MF \"CMakeFiles/execut1.dir/util1.c.o.d\""
 				+ " -o CMakeFiles/execut1.dir/util1.c.o -c /testprojects/C-subsrc/src/src-sub/main1.c";
 		ParseContext result;
@@ -53,14 +53,14 @@ public class MacroDefine_C_POSIXTest {
 		result = new ParseContext();
 		len = testee.processArgument(result, cwd, arg + " " + arg + more);
 		assertTrue("found", result.getDefines().containsKey(name));
-		assertEquals("value", "", result.getDefines().get(name));
+		assertEquals("value", "1", result.getDefines().get(name));
 		assertEquals(2 + name.length(), len);
 		// -D FOO
 		result = new ParseContext();
 		arg = "-D   " + name;
 		len = testee.processArgument(result, cwd, arg + " " + arg + more);
 		assertTrue("found", result.getDefines().containsKey(name));
-		assertEquals("value", "", result.getDefines().get(name));
+		assertEquals("value", "1", result.getDefines().get(name));
 		assertEquals(2 + name.length() + 3, len);
 	}
 
diff --git a/jsoncdb/org.eclipse.cdt.jsoncdb.core.tests/src/org/eclipse/cdt/jsoncdb/core/internal/ToolCommandlineParserTest.java b/jsoncdb/org.eclipse.cdt.jsoncdb.core.tests/src/org/eclipse/cdt/jsoncdb/core/internal/ToolCommandlineParserTest.java
index 7415a793f5d..0eb5714b103 100644
--- a/jsoncdb/org.eclipse.cdt.jsoncdb.core.tests/src/org/eclipse/cdt/jsoncdb/core/internal/ToolCommandlineParserTest.java
+++ b/jsoncdb/org.eclipse.cdt.jsoncdb.core.tests/src/org/eclipse/cdt/jsoncdb/core/internal/ToolCommandlineParserTest.java
@@ -64,7 +64,7 @@ public class ToolCommandlineParserTest {
 		assertTrue("found", result.getDefines().containsKey(def2Name));
 		assertEquals("value", "987", result.getDefines().get(def2Name));
 		assertTrue("found", result.getDefines().containsKey(defName));
-		assertEquals("value", "", result.getDefines().get(defName));
+		assertEquals("value", "1", result.getDefines().get(defName));
 
 		assertEquals("#paths", 1, result.getSystemIncludePaths().size());
 		assertEquals("value", cwdP.resolve(incDirName).toString(), result.getSystemIncludePaths().get(0));
@@ -77,7 +77,7 @@ public class ToolCommandlineParserTest {
 		assertTrue("found", result.getDefines().containsKey(def2Name));
 		assertEquals("value", "987", result.getDefines().get(def2Name));
 		assertTrue("found", result.getDefines().containsKey(defName));
-		assertEquals("value", "", result.getDefines().get(defName));
+		assertEquals("value", "1", result.getDefines().get(defName));
 
 		assertEquals("#paths", 1, result.getSystemIncludePaths().size());
 		assertEquals("value", cwdP.resolve(incDirName).toString(), result.getSystemIncludePaths().get(0));
diff --git a/jsoncdb/org.eclipse.cdt.jsoncdb.core/src/org/eclipse/cdt/jsoncdb/core/internal/builtins/RawSourceFileInfo.java b/jsoncdb/org.eclipse.cdt.jsoncdb.core/src/org/eclipse/cdt/jsoncdb/core/internal/builtins/RawSourceFileInfo.java
index a7c7daf95ff..480861339ae 100644
--- a/jsoncdb/org.eclipse.cdt.jsoncdb.core/src/org/eclipse/cdt/jsoncdb/core/internal/builtins/RawSourceFileInfo.java
+++ b/jsoncdb/org.eclipse.cdt.jsoncdb.core/src/org/eclipse/cdt/jsoncdb/core/internal/builtins/RawSourceFileInfo.java
@@ -21,8 +21,8 @@ import java.util.Map.Entry;
 import java.util.Objects;
 
 import org.eclipse.cdt.jsoncdb.core.internal.Plugin;
-import org.eclipse.cdt.jsoncdb.core.participant.IRawSourceFileInfoCollector;
 import org.eclipse.cdt.jsoncdb.core.participant.IRawSourceFileInfo;
+import org.eclipse.cdt.jsoncdb.core.participant.IRawSourceFileInfoCollector;
 import org.eclipse.core.runtime.Platform;
 
 /**
@@ -46,7 +46,7 @@ public class RawSourceFileInfo implements IRawSourceFileInfo, IRawSourceFileInfo
 	@Override
 	public void addDefine(String name, String value) {
 		Objects.requireNonNull(name);
-		value = Objects.toString(value, ""); //$NON-NLS-1$
+		value = Objects.toString(value, "1"); //$NON-NLS-1$
 		if (DEBUG)
 			System.out.printf("    Added define: %s=%s%n", name, value); //$NON-NLS-1$
 		defines.put(name, value);