diff --git a/modules/alphamat/src/cm.cpp b/modules/alphamat/src/cm.cpp
index 19dcb961e4a..660962eba39 100644
--- a/modules/alphamat/src/cm.cpp
+++ b/modules/alphamat/src/cm.cpp
@@ -90,7 +90,7 @@ void lle(my_vector_of_vectors_t& indm, my_vector_of_vectors_t& samples, float ep
     Mat ptDotN(20, 1, DataType<float>::type), imd(20, 1, DataType<float>::type);
     Mat Cones(20, 1, DataType<float>::type), Cinv(20, 1, DataType<float>::type);
     float alpha, beta, lagrangeMult;
-    Cones += 1;
+    Cones = 1;
 
     C = 0;
     rhs = 1;