diff --git a/src/main/java/org/codehaus/mojo/jaxb2/shared/FileSystemUtilities.java b/src/main/java/org/codehaus/mojo/jaxb2/shared/FileSystemUtilities.java
index 62036e02..f6f8221e 100644
--- a/src/main/java/org/codehaus/mojo/jaxb2/shared/FileSystemUtilities.java
+++ b/src/main/java/org/codehaus/mojo/jaxb2/shared/FileSystemUtilities.java
@@ -539,14 +539,13 @@ public static String relativize(final String path, final File parentDir, final b
         String platformSpecificPath;
         if (p.normalize().startsWith(pd.normalize().toString())) {
             platformSpecificPath = pd.relativize(p).toString();
+            if (removeInitialFileSep && platformSpecificPath.startsWith(File.separator)) {
+                platformSpecificPath = platformSpecificPath.substring(File.separator.length());
+            }
         } else {
             platformSpecificPath = p.toString();
         }
 
-        if (removeInitialFileSep && platformSpecificPath.startsWith(File.separator)) {
-            platformSpecificPath = platformSpecificPath.substring(File.separator.length());
-        }
-
         // NOTE: it appears this function is meant to preserve the file separator that was passed in the path
         if (path.indexOf('\\') == -1) {
             platformSpecificPath = platformSpecificPath.replace('\\', '/');
diff --git a/src/test/java/org/codehaus/mojo/jaxb2/shared/FileSystemUtilitiesTest.java b/src/test/java/org/codehaus/mojo/jaxb2/shared/FileSystemUtilitiesTest.java
index 2f23ba32..01953cec 100644
--- a/src/test/java/org/codehaus/mojo/jaxb2/shared/FileSystemUtilitiesTest.java
+++ b/src/test/java/org/codehaus/mojo/jaxb2/shared/FileSystemUtilitiesTest.java
@@ -427,9 +427,9 @@ public void validateRelativizingPaths() throws Exception {
         final String path = "/project/backend/foobar/my-schema.xsd";
         final SortedMap<String, String> parentDir2Expected = new TreeMap<>();
         parentDir2Expected.put("/", "project/backend/foobar/my-schema.xsd");
-        parentDir2Expected.put("", "project/backend/foobar/my-schema.xsd");
+        parentDir2Expected.put("", "/project/backend/foobar/my-schema.xsd");
         parentDir2Expected.put("/project", "backend/foobar/my-schema.xsd");
-        parentDir2Expected.put("/not/a/path", "project/backend/foobar/my-schema.xsd");
+        parentDir2Expected.put("/not/a/path", "/project/backend/foobar/my-schema.xsd");
         parentDir2Expected.put("/project/", "backend/foobar/my-schema.xsd");
 
         // Act & Assert