diff --git a/src/main/java/com/coveo/pushapiclient/DocumentBuilder.java b/src/main/java/com/coveo/pushapiclient/DocumentBuilder.java
index 2b62053b..a95fe6a1 100644
--- a/src/main/java/com/coveo/pushapiclient/DocumentBuilder.java
+++ b/src/main/java/com/coveo/pushapiclient/DocumentBuilder.java
@@ -360,7 +360,9 @@ private void validateReservedMetadataKeyNames(String key) {
 
     private void generatePermanentId() {
         if (this.document.permanentId == null) {
-            this.document.permanentId = DigestUtils.sha256Hex(this.document.uri);
+            String md5 = DigestUtils.md5Hex(this.document.uri);
+            String sha1 = DigestUtils.sha1Hex(this.document.uri);
+            this.document.permanentId = md5.substring(0, 30) + sha1.substring(0, 30);
         }
     }
 }
diff --git a/src/test/java/com/coveo/pushapiclient/DocumentBuilderTest.java b/src/test/java/com/coveo/pushapiclient/DocumentBuilderTest.java
index 6a5dcdac..43f3cf61 100644
--- a/src/test/java/com/coveo/pushapiclient/DocumentBuilderTest.java
+++ b/src/test/java/com/coveo/pushapiclient/DocumentBuilderTest.java
@@ -132,9 +132,11 @@ public void testWithPermanentId() {
 
     @Test
     public void testWithPermanentIdGeneration() {
-        assertTrue(
+        docBuilder = new DocumentBuilder("https://foo.com", "bar");
+        assertEquals(
                 "permanentId should be generated automatically if not set",
-                docBuilder.marshalJsonObject().get("permanentId").getAsString().length() > 0
+                "aa2e0510b66edff7f05e2b30d4f1b3a4b5481c06b69f41751c54675c5afb",
+                docBuilder.marshalJsonObject().get("permanentId").getAsString()
         );
     }
 
@@ -373,4 +375,4 @@ public void marshal() {
         );
     }
 
-}
\ No newline at end of file
+}