diff --git a/org.eclipse.m2e.core.tests/resources/projects/gitVersioningExtension/.mvn/extensions.xml b/org.eclipse.m2e.core.tests/resources/projects/gitVersioningExtension/.mvn/extensions.xml
new file mode 100644
index 0000000000..4291456896
--- /dev/null
+++ b/org.eclipse.m2e.core.tests/resources/projects/gitVersioningExtension/.mvn/extensions.xml
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<extensions>
+	<extension>
+		<groupId>me.qoomon</groupId>
+		<artifactId>maven-git-versioning-extension</artifactId>
+		<version>9.11.0</version>
+	</extension>
+</extensions>
diff --git a/org.eclipse.m2e.core.tests/resources/projects/gitVersioningExtension/pom.xml b/org.eclipse.m2e.core.tests/resources/projects/gitVersioningExtension/pom.xml
new file mode 100644
index 0000000000..479083cb46
--- /dev/null
+++ b/org.eclipse.m2e.core.tests/resources/projects/gitVersioningExtension/pom.xml
@@ -0,0 +1,6 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>test</groupId>
+	<artifactId>git-versioning-test</artifactId>
+	<version>1.0.0-SNAPSHOT</version>
+</project>
diff --git a/org.eclipse.m2e.core.tests/src/org/eclipse/m2e/core/ExtensionsTest.java b/org.eclipse.m2e.core.tests/src/org/eclipse/m2e/core/ExtensionsTest.java
index 8c728d1783..e191c3296b 100644
--- a/org.eclipse.m2e.core.tests/src/org/eclipse/m2e/core/ExtensionsTest.java
+++ b/org.eclipse.m2e.core.tests/src/org/eclipse/m2e/core/ExtensionsTest.java
@@ -13,6 +13,7 @@
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 
+import java.io.File;
 import java.io.IOException;
 import java.util.Collection;
 
@@ -104,6 +105,24 @@ public void testCopyResourcesWithMVNFolder() throws Exception {
 		assertEquals("foo-bar-content", new String(file.getContents().readAllBytes()));
 	}
 
+	@Test
+	public void testGitVersioningExtension() throws Exception {
+		// Pre-initialize git repo in workspace (required by the extension to activate)
+		File projectDir = new File(workspace.getRoot().getLocation().toFile(), "gitVersioningExtension");
+		copyDir(new File("resources/projects/gitVersioningExtension"), projectDir);
+		assertEquals(0, new ProcessBuilder("git", "init").directory(projectDir).start().waitFor());
+		assertEquals(0, new ProcessBuilder("git", "add", ".").directory(projectDir).start().waitFor());
+		assertEquals(0,
+				new ProcessBuilder("git", "-c", "user.email=test@test.com", "-c", "user.name=Test", "commit", "-m",
+						"init").directory(projectDir).start().waitFor());
+		// Import project - the extension modifies the model, stripping InputLocation metadata
+		IProject project = importProject("resources/projects/gitVersioningExtension/pom.xml");
+		waitForJobsToComplete(monitor);
+		// Without the fix, Model.getLocation("") returns null causing NPE in
+		// AnnotationMappingMetadataSource and SourceLocationHelper
+		assertNoErrors(project);
+	}
+
 	private IProject importPomlessProject(String rootProject, String... poms) throws IOException, CoreException {
 		IProject[] projects = importProjects("resources/projects/" + rootProject + "/", poms,
 				new ResolverConfiguration(), false);
diff --git a/org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/lifecyclemapping/AnnotationMappingMetadataSource.java b/org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/lifecyclemapping/AnnotationMappingMetadataSource.java
index 9f67733d66..f13a015f90 100644
--- a/org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/lifecyclemapping/AnnotationMappingMetadataSource.java
+++ b/org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/lifecyclemapping/AnnotationMappingMetadataSource.java
@@ -79,7 +79,12 @@ public static AnnotationMappingMetadataSource get(MavenProject project) {
   private AnnotationMappingMetadataSource(MavenProject project, List<PI> pis) {
     this.project = project;
     this.pis = pis;
-    projectId = project.getModel().getLocation(SELF).getSource().getModelId();
+    InputLocation selfLocation = project.getModel().getLocation(SELF);
+    if(selfLocation != null && selfLocation.getSource() != null) {
+      projectId = selfLocation.getSource().getModelId();
+    } else {
+      projectId = project.getGroupId() + ":" + project.getArtifactId() + ":" + project.getVersion();
+    }
   }
 
   @Override
@@ -171,7 +176,14 @@ private PluginExecutionMetadata createMetadata(Xpp3Dom action) {
   }
 
   private static List<PI> parsePIs(MavenProject project) {
-    InputSource source = project.getModel().getLocation(SELF).getSource();
+    InputLocation selfLocation = project.getModel().getLocation(SELF);
+    if(selfLocation == null) {
+      return List.of();
+    }
+    InputSource source = selfLocation.getSource();
+    if(source == null) {
+      return List.of();
+    }
     File pom = project.getFile();
     if((pom == null || !pom.isFile()) && source.getLocation() != null) {
       pom = new File(source.getLocation());
diff --git a/org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/markers/SourceLocationHelper.java b/org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/markers/SourceLocationHelper.java
index b9ef82895c..be8cde02a8 100644
--- a/org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/markers/SourceLocationHelper.java
+++ b/org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/markers/SourceLocationHelper.java
@@ -117,13 +117,16 @@ public static SourceLocation findLocation(MavenProject mavenProject, MojoExecuti
     }
 
     File pomFile = mavenProject.getFile();
-    if(pomFile.getAbsolutePath().equals(inputLocation.getSource().getLocation())) {
+    if(inputLocation.getSource() != null && pomFile.getAbsolutePath().equals(inputLocation.getSource().getLocation())) {
       // Plugin/execution is specified in current pom
       return getSourceLocation(inputLocation, elementName);
     }
 
     // Plugin/execution is specified in some parent pom
     SourceLocation causeLocation = getSourceLocation(inputLocation, elementName);
+    if(mavenProject.getModel().getParent() == null) {
+      return new SourceLocation(1, 1, 1, causeLocation);
+    }
     inputLocation = mavenProject.getModel().getParent().getLocation(SELF);
     if(inputLocation == null) {
       // parent location cannot be determined for participant-added parents
@@ -156,8 +159,10 @@ private static org.apache.maven.model.Dependency getMavenDependency(MavenProject
         if(found != null) {
 
           // missing transitive managed dependency
-          String projectId = mavenProject.getModel().getLocation(SELF).getSource().getModelId();
-          String depId = found.getLocation(SELF).getSource().getModelId();
+          InputLocation projectSelfLoc = mavenProject.getModel().getLocation(SELF);
+          InputLocation depSelfLoc = found.getLocation(SELF);
+          String projectId = projectSelfLoc != null && projectSelfLoc.getSource() != null ? projectSelfLoc.getSource().getModelId() : null;
+          String depId = depSelfLoc != null && depSelfLoc.getSource() != null ? depSelfLoc.getSource().getModelId() : null;
 
           if(!projectId.equals(depId)) {
             // let's see if it comes from a directly imported pom
@@ -224,32 +229,44 @@ public static SourceLocation findLocation(MavenProject mavenProject, org.apache.
     if(inputLocation == null) {
       // Should never happen
       inputLocation = mavenProject.getModel().getLocation(SELF);
+      if(inputLocation == null) {
+        return new SourceLocation(1, 1, 1);
+      }
       return new SourceLocation(inputLocation.getLineNumber(), 1, inputLocation.getColumnNumber() - COLUMN_END_OFFSET);
     }
 
     File pomFile = mavenProject.getFile();
-    if(pomFile.getAbsolutePath().equals(inputLocation.getSource().getLocation())) {
+    if(inputLocation.getSource() != null && pomFile.getAbsolutePath().equals(inputLocation.getSource().getLocation())) {
       // Dependency is specified in current pom
       return getSourceLocation(inputLocation, DEPENDENCY);
     }
 
-    // Plugin/execution is specified in some parent pom
+    // Dependency is specified in some parent pom
     SourceLocation causeLocation = getSourceLocation(inputLocation, DEPENDENCY);
+    if(mavenProject.getModel().getParent() == null) {
+      return new SourceLocation(1, 1, 1, causeLocation);
+    }
     inputLocation = mavenProject.getModel().getParent().getLocation(SELF);
     return getSourceLocation(inputLocation, PARENT, causeLocation);
   }
 
   private static SourceLocation getSourceLocation(InputLocation inputLocation, String elementName) {
+    if(inputLocation == null) {
+      return new SourceLocation(1, 1, 1);
+    }
     InputSource source = inputLocation.getSource();
     return new SourceLocation( //
         source != null ? source.getLocation() : null, source != null ? source.getModelId() : null,
-        inputLocation.getLineNumber(), //  
+        inputLocation.getLineNumber(), //
         inputLocation.getColumnNumber() - elementName.length() - COLUMN_START_OFFSET,
         inputLocation.getColumnNumber() - COLUMN_END_OFFSET);
   }
 
   private static SourceLocation getSourceLocation(InputLocation inputLocation, String elementName,
       SourceLocation causeLocation) {
+    if(inputLocation == null) {
+      return new SourceLocation(1, 1, 1, causeLocation);
+    }
     return new SourceLocation(inputLocation.getLineNumber(),
         inputLocation.getColumnNumber() - elementName.length() - COLUMN_START_OFFSET,
         inputLocation.getColumnNumber() - COLUMN_END_OFFSET, causeLocation);