diff --git a/modules/gpu/src/cuda/optical_flow.cu b/modules/gpu/src/cuda/optical_flow.cu
index 800eb6f5d..9406cce93 100644
--- a/modules/gpu/src/cuda/optical_flow.cu
+++ b/modules/gpu/src/cuda/optical_flow.cu
@@ -138,7 +138,7 @@ namespace cv { namespace gpu { namespace device
                 const float u_avg_val = u_avg(y, x);
                 const float v_avg_val = v_avg(y, x);
 
-                const float theta = ::atan2f(v_avg_val, u_avg_val) + CV_PI;
+                const float theta = ::atan2f(v_avg_val, u_avg_val);// + CV_PI;
 
                 float r = ::sqrtf(v_avg_val * v_avg_val + u_avg_val * u_avg_val);
                 r = fmin(14.0f * (r / max_flow), 14.0f);
diff --git a/samples/gpu/optical_flow.cpp b/samples/gpu/optical_flow.cpp
index 30022bbb8..c3015286a 100644
--- a/samples/gpu/optical_flow.cpp
+++ b/samples/gpu/optical_flow.cpp
@@ -129,7 +129,7 @@ int main(int argc, const char* argv[])
         
         GpuMat d_vertex, d_colors;
 
-        createOpticalFlowNeedleMap(d_bu, d_bv, d_vertex, d_colors);
+        createOpticalFlowNeedleMap(d_fu, d_fv, d_vertex, d_colors);
 #endif
 
         cout << "Interpolating..." << endl;