diff --git a/cmd-capture-pane.c b/cmd-capture-pane.c
index 52f5455c..bdf74106 100644
--- a/cmd-capture-pane.c
+++ b/cmd-capture-pane.c
@@ -60,9 +60,10 @@ cmd_capture_pane_exec(struct cmd *self, struct cmd_ctx *ctx)
 	len = 0;
 
 	n = args_strtonum(args, 'S', SHRT_MIN, SHRT_MAX, &cause);
-	if (cause != NULL)
+	if (cause != NULL) {
 		top = gd->hsize;
-	else if (n < 0 && (u_int) -n > gd->hsize)
+		xfree(cause);
+	} else if (n < 0 && (u_int) -n > gd->hsize)
 		top = 0;
 	else
 		top = gd->hsize + n;
@@ -70,9 +71,10 @@ cmd_capture_pane_exec(struct cmd *self, struct cmd_ctx *ctx)
 		top = gd->hsize + gd->sy - 1;
 
 	n = args_strtonum(args, 'E', SHRT_MIN, SHRT_MAX, &cause);
-	if (cause != NULL)
+	if (cause != NULL) {
 		bottom = gd->hsize + gd->sy - 1;
-	else if (n < 0 && (u_int) -n > gd->hsize)
+		xfree(cause);
+	} else if (n < 0 && (u_int) -n > gd->hsize)
 		bottom = 0;
 	else
 		bottom = gd->hsize + n;