diff --git a/src/base/ftstroke.c b/src/base/ftstroke.c
index 64f46ce43..40d74d6e4 100644
--- a/src/base/ftstroke.c
+++ b/src/base/ftstroke.c
@@ -1371,7 +1371,7 @@
     arc[1] = *control;
     arc[2] = stroker->center;
 
-    while ( arc >= bez_stack )
+    do
     {
       FT_Angle  angle_in, angle_out;
 
@@ -1524,10 +1524,12 @@
         }
       }
 
-      arc -= 2;
-
       stroker->angle_in = angle_out;
-    }
+
+      if ( arc == bez_stack )
+        break;
+      arc -= 2;
+    } while ( 1 );
 
     stroker->center      = *to;
     stroker->line_length = 0;
@@ -1577,7 +1579,7 @@
     arc[2] = *control1;
     arc[3] = stroker->center;
 
-    while ( arc >= bez_stack )
+    do
     {
       FT_Angle  angle_in, angle_mid, angle_out;
 
@@ -1741,10 +1743,12 @@
         }
       }
 
-      arc -= 3;
-
       stroker->angle_in = angle_out;
-    }
+
+      if ( arc == bez_stack )
+        break;
+      arc -= 3;
+    } while ( 1 );
 
     stroker->center      = *to;
     stroker->line_length = 0;