diff --git a/completions/bash/feedgnuplot b/completions/bash/feedgnuplot
index 0bf6219..81460b1 100644
--- a/completions/bash/feedgnuplot
+++ b/completions/bash/feedgnuplot
@@ -20,6 +20,7 @@ complete -W               \
     --extracmds           \
     --set                 \
     --unset               \
+    --equation            \
     --geometry            \
     --hardcopy            \
     --help                \
diff --git a/completions/zsh/_feedgnuplot b/completions/zsh/_feedgnuplot
index c2e710a..f29c20f 100644
--- a/completions/zsh/_feedgnuplot
+++ b/completions/zsh/_feedgnuplot
@@ -32,6 +32,7 @@ _arguments -S
     '*--extracmds[Additional gnuplot commands]:command'                           \
     '*--set[Additional 'set' gnuplot commands]:set-option'                        \
     '*--unset[Additional 'unset' gnuplot commands]:unset-option'                  \
+    '*--equation[Raw symbolic equation]:equation'                                 \
     '--square[Plot data with square aspect ratio]'                                \
     '--square_xy[For 3D plots, set square aspect ratio for ONLY the x,y axes]'    \
     '--hardcopy[Plot to a file]:filename'                                         \