diff --git a/src/psprint.c b/src/psprint.c
index ce7ffbcf..44a30991 100644
--- a/src/psprint.c
+++ b/src/psprint.c
@@ -606,6 +606,11 @@ static void ps_drawarc(int gc, int fillarc, double x,double y,double r,double a,
  double x1, y1, x2, y2;
  double psdash;
 
+  if(b < 0.0) {
+    a = a + b;
+    b = -b;
+  }
+
   xx=X_TO_PS(x);
   yy=Y_TO_PS(y);
   rr=r*xctx->mooz;
diff --git a/src/svgdraw.c b/src/svgdraw.c
index b8a9fe66..e45d76f5 100644
--- a/src/svgdraw.c
+++ b/src/svgdraw.c
@@ -237,6 +237,10 @@ static void svg_drawarc(int gc, int fillarc, double x,double y,double r,double a
  double xx1, yy1, xx2, yy2;
  int fs, fa;
 
+  if(b < 0.0) {
+    a = a + b;
+    b = -b;
+  }
   xx=X_TO_SCREEN(x);
   yy=Y_TO_SCREEN(y);
   rr=r*xctx->mooz;