diff --git a/CHANGELOG.md b/CHANGELOG.md
index c31c1e8e..20b6a973 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -33,6 +33,8 @@ New constraint features:
     in the text window.
   * When selecting an entity, the constraints applied to it can be selected
     in the text window.
+  * It is now possible to turn off automatic creation of horizontal/vertical
+    constraints on line segments.
 
 New export/import features:
   * Three.js: allow configuring projection for exported model, and initially
diff --git a/src/confscreen.cpp b/src/confscreen.cpp
index 7c8d54b2..c7e193c1 100644
--- a/src/confscreen.cpp
+++ b/src/confscreen.cpp
@@ -93,6 +93,11 @@ void TextWindow::ScreenChangeCheckClosedContour(int link, uint32_t v) {
     SS.GW.Invalidate();
 }
 
+void TextWindow::ScreenChangeAutomaticLineConstraints(int link, uint32_t v) {
+    SS.automaticLineConstraints = !SS.automaticLineConstraints;
+    SS.GW.Invalidate();
+}
+
 void TextWindow::ScreenChangeShadedTriangles(int link, uint32_t v) {
     SS.exportShadedTriangles = !SS.exportShadedTriangles;
     SS.GW.Invalidate();
@@ -301,6 +306,9 @@ void TextWindow::ShowConfiguration() {
     Printf(false, "  %Fd%f%Ll%s  check sketch for closed contour%E",
         &ScreenChangeCheckClosedContour,
         SS.checkClosedContour ? CHECK_TRUE : CHECK_FALSE);
+    Printf(false, "  %Fd%f%Ll%s  enable automatic line constraints%E",
+        &ScreenChangeAutomaticLineConstraints,
+        SS.automaticLineConstraints ? CHECK_TRUE : CHECK_FALSE);
     Printf(false, "  %Fd%f%Ll%s  show areas of closed contours%E",
         &ScreenChangeShowContourAreas,
         SS.showContourAreas ? CHECK_TRUE : CHECK_FALSE);
diff --git a/src/graphicswin.cpp b/src/graphicswin.cpp
index a6d623e7..414c6ec4 100644
--- a/src/graphicswin.cpp
+++ b/src/graphicswin.cpp
@@ -1283,26 +1283,27 @@ void GraphicsWindow::ToggleBool(bool *v) {
 }
 
 bool GraphicsWindow::SuggestLineConstraint(hRequest request, Constraint::Type *type) {
-    if(LockedInWorkplane()) {
-        Entity *ptA = SK.GetEntity(request.entity(1)),
-               *ptB = SK.GetEntity(request.entity(2));
+    if(!(LockedInWorkplane() && SS.automaticLineConstraints))
+        return false;
 
-        Expr *au, *av, *bu, *bv;
+    Entity *ptA = SK.GetEntity(request.entity(1)),
+           *ptB = SK.GetEntity(request.entity(2));
 
-        ptA->PointGetExprsInWorkplane(ActiveWorkplane(), &au, &av);
-        ptB->PointGetExprsInWorkplane(ActiveWorkplane(), &bu, &bv);
+    Expr *au, *av, *bu, *bv;
 
-        double du = au->Minus(bu)->Eval();
-        double dv = av->Minus(bv)->Eval();
+    ptA->PointGetExprsInWorkplane(ActiveWorkplane(), &au, &av);
+    ptB->PointGetExprsInWorkplane(ActiveWorkplane(), &bu, &bv);
 
-        const double TOLERANCE_RATIO = 0.02;
-        if(fabs(dv) > LENGTH_EPS && fabs(du / dv) < TOLERANCE_RATIO) {
-            *type = Constraint::Type::VERTICAL;
-            return true;
-        } else if(fabs(du) > LENGTH_EPS && fabs(dv / du) < TOLERANCE_RATIO) {
-            *type = Constraint::Type::HORIZONTAL;
-            return true;
-        }
+    double du = au->Minus(bu)->Eval();
+    double dv = av->Minus(bv)->Eval();
+
+    const double TOLERANCE_RATIO = 0.02;
+    if(fabs(dv) > LENGTH_EPS && fabs(du / dv) < TOLERANCE_RATIO) {
+        *type = Constraint::Type::VERTICAL;
+        return true;
+    } else if(fabs(du) > LENGTH_EPS && fabs(dv / du) < TOLERANCE_RATIO) {
+        *type = Constraint::Type::HORIZONTAL;
+        return true;
     }
     return false;
 }
diff --git a/src/solvespace.cpp b/src/solvespace.cpp
index 7e643646..210c2904 100644
--- a/src/solvespace.cpp
+++ b/src/solvespace.cpp
@@ -70,6 +70,8 @@ void SolveSpaceUI::Init() {
     drawBackFaces = settings->ThawBool("DrawBackFaces", true);
     // Check that contours are closed and not self-intersecting
     checkClosedContour = settings->ThawBool("CheckClosedContour", true);
+    // Enable automatic constrains for lines
+    automaticLineConstraints = settings->ThawBool("AutomaticLineConstraints", true);
     // Draw closed polygons areas
     showContourAreas = settings->ThawBool("ShowContourAreas", false);
     // Export shaded triangles in a 2d view
@@ -241,6 +243,8 @@ void SolveSpaceUI::Exit() {
     settings->FreezeBool("ShowContourAreas", showContourAreas);
     // Check that contours are closed and not self-intersecting
     settings->FreezeBool("CheckClosedContour", checkClosedContour);
+    // Enable automatic constrains for lines
+    settings->FreezeBool("AutomaticLineConstraints", automaticLineConstraints);
     // Export shaded triangles in a 2d view
     settings->FreezeBool("ExportShadedTriangles", exportShadedTriangles);
     // Export pwl curves (instead of exact) always
diff --git a/src/solvespace.h b/src/solvespace.h
index 8e911929..9c788567 100644
--- a/src/solvespace.h
+++ b/src/solvespace.h
@@ -590,6 +590,7 @@ public:
     bool     drawBackFaces;
     bool     showContourAreas;
     bool     checkClosedContour;
+    bool     automaticLineConstraints;
     bool     showToolbar;
     Platform::Path screenshotFile;
     RgbaColor backgroundColor;
diff --git a/src/ui.h b/src/ui.h
index fcbcffb9..cb6f06a6 100644
--- a/src/ui.h
+++ b/src/ui.h
@@ -425,6 +425,7 @@ public:
     static void ScreenChangeBackFaces(int link, uint32_t v);
     static void ScreenChangeShowContourAreas(int link, uint32_t v);
     static void ScreenChangeCheckClosedContour(int link, uint32_t v);
+    static void ScreenChangeAutomaticLineConstraints(int link, uint32_t v);
     static void ScreenChangePwlCurves(int link, uint32_t v);
     static void ScreenChangeCanvasSizeAuto(int link, uint32_t v);
     static void ScreenChangeCanvasSize(int link, uint32_t v);