diff --git a/src/HLRAlgo/HLRAlgo_PolyData.cxx b/src/HLRAlgo/HLRAlgo_PolyData.cxx
index 333920e723..95d4fbdbaf 100644
--- a/src/HLRAlgo/HLRAlgo_PolyData.cxx
+++ b/src/HLRAlgo/HLRAlgo_PolyData.cxx
@@ -470,7 +470,7 @@ void HLRAlgo_PolyData::hideByOneTriangle (const HLRAlgo_BiPoint::PointsT& thePoi
     if (d2 < 0) ad2 = -d2;
     pp = ad1 / ( ad1 + ad2 );
     if (TrFlags & HLRAlgo_PolyMask_EMskGrALin2)
-      pdp = (thePoints.PntP1.X() + (thePoints.Pnt2.X() - thePoints.PntP1.X()) * pp - theTriangle.V2.X()) / aD.X();
+      pdp = (thePoints.PntP1.X() + (thePoints.PntP2.X() - thePoints.PntP1.X()) * pp - theTriangle.V2.X()) / aD.X();
     else
       pdp = (thePoints.PntP1.Y() + (thePoints.PntP2.Y() - thePoints.PntP1.Y()) * pp - theTriangle.V2.Y()) / aD.Y();
     Standard_Boolean OutSideP = Standard_False;
diff --git a/tests/bugs/modalg_7/bug28784 b/tests/bugs/modalg_7/bug28784
index 5289bd6460..2ae78b2a2a 100755
--- a/tests/bugs/modalg_7/bug28784
+++ b/tests/bugs/modalg_7/bug28784
@@ -11,7 +11,7 @@ pload QAcommands
 restore [locate_data_file bug28784_MHX_SKG_MS_Pos1_simplified.brep] a
 OCC28784 result a
 
-checknbshapes result -edge 236
+checknbshapes result -edge 235
 
 smallview
 top
diff --git a/tests/bugs/modalg_7/bug29956 b/tests/bugs/modalg_7/bug29956
new file mode 100644
index 0000000000..f7cdcb4d3e
--- /dev/null
+++ b/tests/bugs/modalg_7/bug29956
@@ -0,0 +1,14 @@
+puts "========"
+puts "0029956: HLR polygonal algorithm: regression in 7.1 relative to 7.0"
+puts "========"
+puts ""
+
+pload XSDRAW
+testreadstep [locate_data_file example_auto_tooling_01.stp] s
+vinit
+vdisplay s
+vfit
+vhlrtype polyAlgo s
+vhlr on
+
+vdump ${imagedir}/${casename}.png
diff --git a/tests/bugs/modalg_7/bug30243 b/tests/bugs/modalg_7/bug30243
new file mode 100644
index 0000000000..8dc14239e1
--- /dev/null
+++ b/tests/bugs/modalg_7/bug30243
@@ -0,0 +1,14 @@
+puts "========"
+puts "0030243: Regression in HLR PolyAlgo in OCCT 7.1.0"
+puts "========"
+puts ""
+
+pload XSDRAW
+testreadstep [locate_data_file BFC_10000.stp] s
+vinit
+vdisplay s
+vfit
+vhlrtype polyAlgo s
+vhlr on
+
+vdump ${imagedir}/${casename}.png