diff --git a/cas-client-core/src/main/java/org/jasig/cas/client/util/AssertionThreadLocalFilter.java b/cas-client-core/src/main/java/org/jasig/cas/client/util/AssertionThreadLocalFilter.java
index 4be9d65..4938a17 100644
--- a/cas-client-core/src/main/java/org/jasig/cas/client/util/AssertionThreadLocalFilter.java
+++ b/cas-client-core/src/main/java/org/jasig/cas/client/util/AssertionThreadLocalFilter.java
@@ -33,7 +33,7 @@ public final class AssertionThreadLocalFilter implements Filter {
     public void doFilter(final ServletRequest servletRequest, final ServletResponse servletResponse, final FilterChain filterChain) throws IOException, ServletException {
         final HttpServletRequest request = (HttpServletRequest) servletRequest;
         final HttpSession session = request.getSession(false);
-        final Assertion assertion = (Assertion) (session != null ? session.getAttribute(AbstractCasFilter.CONST_CAS_ASSERTION) : null);
+        final Assertion assertion = (Assertion) (session == null ? request.getAttribute(AbstractCasFilter.CONST_CAS_ASSERTION) : session.getAttribute(AbstractCasFilter.CONST_CAS_ASSERTION));
 
         try {
             AssertionHolder.setAssertion(assertion);