diff --git a/src/algorithms/input_filter/gnuradio_blocks/beamformer.cc b/src/algorithms/input_filter/gnuradio_blocks/beamformer.cc
index 165890e66..726ae6bd2 100644
--- a/src/algorithms/input_filter/gnuradio_blocks/beamformer.cc
+++ b/src/algorithms/input_filter/gnuradio_blocks/beamformer.cc
@@ -67,7 +67,7 @@ int beamformer::work(int noutput_items, gr_vector_const_void_star &input_items,
     for (int n = 0; n < noutput_items; n++)
         {
             sum = gr_complex(0, 0);
-            for (int i = 0; i < weight_vector.size(); i++)
+            for (unsigned int i = 0; i < weight_vector.size(); i++)
                 {
                     sum = sum + (reinterpret_cast<const gr_complex *>(input_items[i]))[n] * weight_vector[i];
                 }