diff --git a/zigzag/core.pyx b/zigzag/core.pyx
index bcff651..41f048c 100644
--- a/zigzag/core.pyx
+++ b/zigzag/core.pyx
@@ -115,7 +115,7 @@ cpdef peak_valley_pivots(double [:] X,
                 last_pivot_x = x
                 last_pivot_t = t
 
-    if last_pivot_t == t_n-1:
+    if last_pivot_t != t_n-1:
         pivots[last_pivot_t] = trend
     elif pivots[t_n-1] == 0:
         pivots[t_n-1] = -trend