diff --git a/src/IntAna/IntAna_QuadQuadGeo.cxx b/src/IntAna/IntAna_QuadQuadGeo.cxx
index f015b93223..79a3ed250f 100644
--- a/src/IntAna/IntAna_QuadQuadGeo.cxx
+++ b/src/IntAna/IntAna_QuadQuadGeo.cxx
@@ -2473,33 +2473,32 @@ void IntAna_QuadQuadGeo::Perform(const gp_Torus& Tor1,
   aRMaj1 = Tor1.MajorRadius();
   aRMin2 = Tor2.MinorRadius();
   aRMaj2 = Tor2.MajorRadius();
-  if (aRMin1 >= aRMaj1 || aRMin2 >= aRMaj2) {
-    typeres = IntAna_NoGeometricSolution;
-    return;
-  }
   //
-  const gp_Ax1 anAx1 = Tor1.Axis();
-  const gp_Ax1 anAx2 = Tor2.Axis();
+  const gp_Ax1& anAx1 = Tor1.Axis();
+  const gp_Ax1& anAx2 = Tor2.Axis();
+  //
+  const gp_Pnt& aLoc1 = anAx1.Location();
+  const gp_Pnt& aLoc2 = anAx2.Location();
   //
   gp_Lin aL1(anAx1);
   if (!anAx1.IsParallel(anAx2, myEPSILON_AXES_PARA) ||
-      (aL1.Distance(anAx2.Location()) > myEPSILON_DISTANCE)) {
+      (aL1.Distance(aLoc2) > myEPSILON_DISTANCE)) {
     typeres = IntAna_NoGeometricSolution;
     return;
   }
   //
-  gp_Pnt aLoc1, aLoc2;
-  //
-  aLoc1 = anAx1.Location();
-  aLoc2 = anAx2.Location();
-  //
   if (aLoc1.IsEqual(aLoc2, Tol) &&
-      (Abs(aRMin1 - aRMin2) <= Tol) && 
+      (Abs(aRMin1 - aRMin2) <= Tol) &&
       (Abs(aRMaj1 - aRMaj2) <= Tol)) {
     typeres = IntAna_Same;
     return;
   }
   //
+  if (aRMin1 >= aRMaj1 || aRMin2 >= aRMaj2) {
+    typeres = IntAna_NoGeometricSolution;
+    return;
+  }
+  //
   Standard_Real aDist;
   gp_Pnt aP1, aP2;
   //
diff --git a/src/IntPatch/IntPatch_Intersection.cxx b/src/IntPatch/IntPatch_Intersection.cxx
index cea146a9f4..f749781335 100644
--- a/src/IntPatch/IntPatch_Intersection.cxx
+++ b/src/IntPatch/IntPatch_Intersection.cxx
@@ -1072,7 +1072,9 @@ void IntPatch_Intersection::Perform(const Handle(Adaptor3d_HSurface)&  theS1,
       bToCheck = aTor1.MajorRadius() > aTor1.MinorRadius();
       if (typs1 == typs2) {
         const gp_Torus aTor2 = aGeomSurf->Torus();
-        bToCheck = aTor2.MajorRadius() > aTor2.MinorRadius();
+        bToCheck = (bToCheck && (aTor2.MajorRadius() > aTor2.MinorRadius())) ||
+                   (Abs(aTor1.MajorRadius() - aTor2.MajorRadius()) < TolTang &&
+                    Abs(aTor1.MinorRadius() - aTor2.MinorRadius()) < TolTang);
       }
       //
       if (aCTType == GeomAbs_Torus) {
diff --git a/tests/bugs/modalg_7/bug30100_1 b/tests/bugs/modalg_7/bug30100_1
new file mode 100644
index 0000000000..7cb3882d83
--- /dev/null
+++ b/tests/bugs/modalg_7/bug30100_1
@@ -0,0 +1,12 @@
+puts "========"
+puts "0030100: Modeling Algorithms - ShapeUpgrade_UnifySameDomain is unable to unify faces based on the same toroidal surface"
+puts "========"
+puts ""
+
+restore [locate_data_file bug30100_usd.brep] s
+unifysamedom result s
+checkshape result
+checknbshapes result -wire 1 -face 1
+checkprops result -s 142506
+
+checkview -display result -2d -path ${imagedir}/${test_image}.png
diff --git a/tests/bugs/modalg_7/bug30100_2 b/tests/bugs/modalg_7/bug30100_2
new file mode 100644
index 0000000000..831cc1e8c5
--- /dev/null
+++ b/tests/bugs/modalg_7/bug30100_2
@@ -0,0 +1,11 @@
+puts "========"
+puts "0030100: Modeling Algorithms - ShapeUpgrade_UnifySameDomain is unable to unify faces based on the same toroidal surface"
+puts "========"
+puts ""
+
+restore [locate_data_file bug30100_faces.brep] f
+explode f
+
+if {![regexp "no 3d curves" [bopcurves f_1 f_2]]} {
+  puts "Error: Tangent faces are not detected"
+}