diff --git a/build/org.eclipse.cdt.managedbuilder.core.tests/resources/test30Projects/testFileWithNoExtension/testFileWithNoExtension.zip b/build/org.eclipse.cdt.managedbuilder.core.tests/resources/test30Projects/testFileWithNoExtension/testFileWithNoExtension.zip
new file mode 100644
index 00000000000..409d24e6c34
Binary files /dev/null and b/build/org.eclipse.cdt.managedbuilder.core.tests/resources/test30Projects/testFileWithNoExtension/testFileWithNoExtension.zip differ
diff --git a/build/org.eclipse.cdt.managedbuilder.core.tests/tests/org/eclipse/cdt/managedbuilder/core/tests/ManagedProject30MakefileTests.java b/build/org.eclipse.cdt.managedbuilder.core.tests/tests/org/eclipse/cdt/managedbuilder/core/tests/ManagedProject30MakefileTests.java
index a0b0f3ba5e3..cabd099fd0e 100644
--- a/build/org.eclipse.cdt.managedbuilder.core.tests/tests/org/eclipse/cdt/managedbuilder/core/tests/ManagedProject30MakefileTests.java
+++ b/build/org.eclipse.cdt.managedbuilder.core.tests/tests/org/eclipse/cdt/managedbuilder/core/tests/ManagedProject30MakefileTests.java
@@ -60,6 +60,7 @@ public class ManagedProject30MakefileTests extends TestCase {
 		suite.addTest(new ManagedProject30MakefileTests("test30CopyandDeploy"));
 		suite.addTest(new ManagedProject30MakefileTests("test30DeleteFile"));
 		suite.addTest(new ManagedProject30MakefileTests("test30NoFilesToBuild"));
+		suite.addTest(new ManagedProject30MakefileTests("testFileWithNoExtension"));
 		suite.addTest(new ManagedProject30MakefileTests("testPreAndPostProcessBuildSteps"));
 		suite.addTest(new ManagedProject30MakefileTests("test30_1"));
 		suite.addTest(new ManagedProject30MakefileTests("test30_2"));
@@ -392,6 +393,21 @@ public class ManagedProject30MakefileTests extends TestCase {
 		buildDegenerativeProjects(projects, makefiles);			
 	}
 
+	/**
+	 * (non-Javadoc)
+	 * tests 3.0 managed build system with a project which has a file with no file extesnion
+	 */
+	public void testFileWithNoExtension()
+	{
+		IPath[] makefiles = {
+				 Path.fromOSString("makefile"), 
+				 Path.fromOSString("objects.mk"), 
+				 Path.fromOSString("sources.mk"), 
+				 Path.fromOSString("subdir.mk")};
+		IProject[] projects = createProjects("testFileWithNoExtension", null, null, true);
+		buildProjects(projects, makefiles);
+	}
+	
 	/* (non-Javadoc)
 	 * tests 3.0 style tool integration: create pre-build and post-build steps and verify that 
 	 * the proper commands are generated in the makefile which is created by the managedbuild system
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/makegen/gnu/ManagedBuildGnuToolInfo.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/makegen/gnu/ManagedBuildGnuToolInfo.java
index ccdb97805cf..36db0023288 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/makegen/gnu/ManagedBuildGnuToolInfo.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/makegen/gnu/ManagedBuildGnuToolInfo.java
@@ -228,6 +228,13 @@ public class ManagedBuildGnuToolInfo implements IManagedBuildGnuToolInfo {
 								for (int j=0; j<projResources.length; j++) {
 									if (projResources[j].getType() == IResource.FILE) {
 										String fileExt = projResources[j].getFileExtension();
+										
+										// fix for NPE, bugzilla 99483
+										if(fileExt == null)
+										{
+											fileExt = "";
+										}
+										
 										for (int k=0; k<exts.length; k++) {
 											if (fileExt.equals(exts[k])) {
 												if (!useFileExts) {