diff --git a/CHANGELOG.md b/CHANGELOG.md
index 093d526c..cd57185d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -90,6 +90,8 @@ means foot can be PGO:d in e.g. sandboxed build scripts. See
   overflow into neighboring cells by default. Set
   **tweak.allow-overflowing-double-width-glyphs** to ‘no’ to disable
   this.
+* Sixel default maximum size is now 10000x10000 instead of the current
+  window size.
 
 
 ### Deprecated
diff --git a/pgo/pgo.c b/pgo/pgo.c
index aa73187e..d401e533 100644
--- a/pgo/pgo.c
+++ b/pgo/pgo.c
@@ -13,6 +13,7 @@
 
 #include "async.h"
 #include "config.h"
+#include "sixel.h"
 #include "user-notification.h"
 #include "vt.h"
 
@@ -200,7 +201,12 @@ main(int argc, const char *const *argv)
         .delayed_render_timer = {
             .lower_fd = lower_fd,
             .upper_fd = upper_fd
-        }
+        },
+        .sixel = {
+            .palette_size = SIXEL_MAX_COLORS,
+            .max_width = SIXEL_MAX_WIDTH,
+            .max_height = SIXEL_MAX_HEIGHT,
+        },
     };
 
     tll_push_back(wayl.terms, &term);
diff --git a/sixel.c b/sixel.c
index 46927d07..bf06ef3e 100644
--- a/sixel.c
+++ b/sixel.c
@@ -778,24 +778,6 @@ sixel_unhook(struct terminal *term)
     render_refresh(term);
 }
 
-static unsigned
-max_width(const struct terminal *term)
-{
-    /* foot extension - treat 0 to mean current terminal size */
-    return term->sixel.max_width == 0
-        ? term->cols * term->cell_width
-        : term->sixel.max_width;
-}
-
-static unsigned
-max_height(const struct terminal *term)
-{
-    /* foot extension - treat 0 to mean current terminal size */
-    return term->sixel.max_height == 0
-        ? term->rows * term->cell_height
-        : term->sixel.max_height;
-}
-
 static bool
 resize(struct terminal *term, int new_width, int new_height)
 {
@@ -863,8 +845,8 @@ sixel_add(struct terminal *term, uint32_t color, uint8_t sixel)
 {
     //LOG_DBG("adding sixel %02hhx using color 0x%06x", sixel, color);
 
-    if (term->sixel.pos.col >= max_width(term) ||
-        term->sixel.pos.row * 6 + 5 >= max_height(term))
+    if (term->sixel.pos.col >= term->sixel.max_width ||
+        term->sixel.pos.row * 6 + 5 >= term->sixel.max_height)
     {
         return;
     }
@@ -990,7 +972,7 @@ decgra(struct terminal *term, uint8_t c)
                 pan, pad, pan / pad, ph, pv);
 
         if (ph >= term->sixel.image.height && pv >= term->sixel.image.width &&
-            ph <= max_height(term) && pv <= max_width(term))
+            ph <= term->sixel.max_height && pv <= term->sixel.max_width)
         {
             if (resize(term, ph, pv))
                 term->sixel.image.autosize = false;
@@ -1163,19 +1145,19 @@ sixel_geometry_report_current(struct terminal *term)
 {
     char reply[64];
     snprintf(reply, sizeof(reply), "\033[?2;0;%u;%uS",
-             max_width(term), max_height(term));
+             term->sixel.max_width, term->sixel.max_height);
     term_to_slave(term, reply, strlen(reply));
 
     LOG_DBG("query response for current sixel geometry: %ux%u",
-            max_width(term), max_height(term));
+            term->sixel.max_width, term->sixel.max_height);
 }
 
 void
 sixel_geometry_reset(struct terminal *term)
 {
-    LOG_DBG("sixel geometry reset to %ux%u", max_width(term), max_height(term));
-    term->sixel.max_width = 0;
-    term->sixel.max_height = 0;
+    LOG_DBG("sixel geometry reset to %ux%u", SIXEL_MAX_WIDTH, SIXEL_MAX_HEIGHT);
+    term->sixel.max_width = SIXEL_MAX_WIDTH;
+    term->sixel.max_height = SIXEL_MAX_HEIGHT;
     sixel_geometry_report_current(term);
 }
 
diff --git a/sixel.h b/sixel.h
index 6cd7324e..f72cf260 100644
--- a/sixel.h
+++ b/sixel.h
@@ -3,6 +3,8 @@
 #include "terminal.h"
 
 #define SIXEL_MAX_COLORS 1024u
+#define SIXEL_MAX_WIDTH 10000u
+#define SIXEL_MAX_HEIGHT 10000u
 
 void sixel_fini(struct terminal *term);
 
diff --git a/terminal.c b/terminal.c
index f78e103c..349fd9bf 100644
--- a/terminal.c
+++ b/terminal.c
@@ -1109,6 +1109,8 @@ term_init(const struct config *conf, struct fdm *fdm, struct reaper *reaper,
         },
         .sixel = {
             .palette_size = SIXEL_MAX_COLORS,
+            .max_width = SIXEL_MAX_WIDTH,
+            .max_height = SIXEL_MAX_HEIGHT,
         },
         .hold_at_exit = conf->hold_at_exit,
         .shutdown_cb = shutdown_cb,