diff --git a/src/scimPatch.ts b/src/scimPatch.ts
index d91290fb..fb6aa78b 100644
--- a/src/scimPatch.ts
+++ b/src/scimPatch.ts
@@ -63,6 +63,8 @@ const IS_ARRAY_SEARCH = /(\[|\])/;
 const ARRAY_SEARCH = /^(.+)\[(.+)\]$/;
 // Split path on periods
 const SPLIT_PERIOD = /(?!\B"[^[]*)\.(?![^\]]*"\B)/g;
+// Regex to fetch the URN from a path.
+const URN_MATCH = /^((?:[A-Za-z0-9][A-Za-z0-9.+-]*:)+[A-Za-z0-9.+-]*)/;
 // Valid patch operation, value needs to be in lowercase here.
 const AUTHORIZED_OPERATION = ['remove', 'add', 'replace'];
 
@@ -144,7 +146,10 @@ function validatePatchOperation(operation: ScimPatchOperation): void {
 }
 
 function resolvePaths(path: string): string[] {
-    const uriIndex = path.lastIndexOf(':');
+    // Identify the URN prefix if present
+    const urnPath = path.match(URN_MATCH);
+    // Find the last colon in the urn path
+    const uriIndex = urnPath ? urnPath[1].lastIndexOf(':') : -1;
 
     if (uriIndex < 0) {
         // No schema prefix - this is a core schema path
diff --git a/test/scimPatch.test.ts b/test/scimPatch.test.ts
index 3dc01860..4205c168 100644
--- a/test/scimPatch.test.ts
+++ b/test/scimPatch.test.ts
@@ -1195,6 +1195,23 @@ describe('SCIM PATCH', () => {
             expect(afterPatch.emails[3].newProperty).to.be.an('undefined');         
             return done();
         });
+
+        it('REPLACE: should handle colon in quoted filter values', done => {
+            scimUser.roles = [
+                { value: "3675b69e-8324-4110-bdca-059031aa8da3:admin", type: "admin" },
+                { value: "other-role", type: "user" }
+            ];
+            const expected = "updated";
+            const patch: ScimPatchAddReplaceOperation = {
+                op: 'replace',
+                value: expected,
+                path: 'roles[value eq "3675b69e-8324-4110-bdca-059031aa8da3:admin"].value'
+            };
+            const afterPatch = scimPatch(scimUser, [patch]);
+            expect(afterPatch.roles![0].value).to.be.eq(expected);
+            expect(afterPatch.roles![1].value).to.be.eq("other-role");
+            return done();
+        });
     });
 
     describe('invalid requests', () => {