diff --git a/doc/filters.texi b/doc/filters.texi
index 799740bf6f..83cc0d478f 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -1363,21 +1363,6 @@ The parameters for @var{x} and @var{y} are expressions containing the
 following constants:
 
 @table @option
-@item W, H
-the input width and height
-
-@item tw, text_w
-the width of the rendered text
-
-@item th, text_h
-the height of the rendered text
-
-@item lh, line_h
-the height of each text line
-
-@item sar
-input sample aspect ratio
-
 @item dar
 input display aspect ratio, it is the same as (@var{w} / @var{h}) * @var{sar}
 
@@ -1385,17 +1370,16 @@ input display aspect ratio, it is the same as (@var{w} / @var{h}) * @var{sar}
 horizontal and vertical chroma subsample values. For example for the
 pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
 
-@item max_glyph_w
-maximum glyph width, that is the maximum width for all the glyphs
-contained in the rendered text
+@item line_h, lh
+the height of each text line
 
-@item max_glyph_h
-maximum glyph height, that is the maximum height for all the glyphs
-contained in the rendered text, it is equivalent to @var{ascent} -
-@var{descent}.
+@item main_h, h, H
+the input height
+
+@item main_w, w, W
+the input width
 
 @item max_glyph_a, ascent
-
 the maximum distance from the baseline to the highest/upper grid
 coordinate used to place a glyph outline point, for all the rendered
 glyphs.
@@ -1408,12 +1392,30 @@ used to place a glyph outline point, for all the rendered glyphs.
 This is a negative value, due to the grid's orientation, with the Y axis
 upwards.
 
+@item max_glyph_h
+maximum glyph height, that is the maximum height for all the glyphs
+contained in the rendered text, it is equivalent to @var{ascent} -
+@var{descent}.
+
+@item max_glyph_w
+maximum glyph width, that is the maximum width for all the glyphs
+contained in the rendered text
+
 @item n
 the number of input frame, starting from 0
 
+@item sar
+input sample aspect ratio
+
 @item t
 timestamp expressed in seconds, NAN if the input timestamp is unknown
 
+@item text_h, th
+the height of the rendered text
+
+@item text_w, tw
+the width of the rendered text
+
 @item timecode
 initial timecode representation in "hh:mm:ss[:;.]ff" format. It can be used
 with or without text parameter. @var{rate} option must be specified.
diff --git a/libavfilter/vf_drawtext.c b/libavfilter/vf_drawtext.c
index 5cfe6bf262..e12aa3dd4c 100644
--- a/libavfilter/vf_drawtext.c
+++ b/libavfilter/vf_drawtext.c
@@ -53,23 +53,22 @@
 #endif
 
 static const char *const var_names[] = {
-    "main_w", "w", "W",       ///< width  of the input video
+    "dar",
+    "hsub", "vsub",
+    "line_h", "lh",           ///< line height, same as max_glyph_h
     "main_h", "h", "H",       ///< height of the input video
-    "tw", "text_w",           ///< width  of the rendered text
-    "th", "text_h",           ///< height of the rendered text
-    "max_glyph_w",            ///< max glyph width
-    "max_glyph_h",            ///< max glyph height
+    "main_w", "w", "W",       ///< width  of the input video
     "max_glyph_a", "ascent",  ///< max glyph ascent
     "max_glyph_d", "descent", ///< min glyph descent
-    "line_h", "lh",           ///< line height, same as max_glyph_h
+    "max_glyph_h",            ///< max glyph height
+    "max_glyph_w",            ///< max glyph width
+    "n",                      ///< number of frame
     "sar",
-    "dar",
-    "hsub",
-    "vsub",
+    "t",                      ///< timestamp expressed in seconds
+    "text_h", "th",           ///< height of the rendered text
+    "text_w", "tw",           ///< width  of the rendered text
     "x",
     "y",
-    "n",                      ///< number of frame
-    "t",                      ///< timestamp expressed in seconds
     NULL
 };
 
@@ -90,23 +89,22 @@ static const eval_func2 fun2[] = {
 };
 
 enum var_name {
-    VAR_MAIN_W, VAR_w, VAR_W,
+    VAR_DAR,
+    VAR_HSUB, VAR_VSUB,
+    VAR_LINE_H, VAR_LH,
     VAR_MAIN_H, VAR_h, VAR_H,
-    VAR_TW, VAR_TEXT_W,
-    VAR_TH, VAR_TEXT_H,
-    VAR_MAX_GLYPH_W,
-    VAR_MAX_GLYPH_H,
+    VAR_MAIN_W, VAR_w, VAR_W,
     VAR_MAX_GLYPH_A, VAR_ASCENT,
     VAR_MAX_GLYPH_D, VAR_DESCENT,
-    VAR_LINE_H, VAR_LH,
+    VAR_MAX_GLYPH_H,
+    VAR_MAX_GLYPH_W,
+    VAR_N,
     VAR_SAR,
-    VAR_DAR,
-    VAR_HSUB,
-    VAR_VSUB,
+    VAR_T,
+    VAR_TEXT_H, VAR_TH,
+    VAR_TEXT_W, VAR_TW,
     VAR_X,
     VAR_Y,
-    VAR_N,
-    VAR_T,
     VAR_VARS_NB
 };