diff --git a/CHANGELOG.md b/CHANGELOG.md
index 93da0a58..e6f5043f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- The chat composer now treats the numeric keypad Enter key as a submit shortcut even when the send-key preference is set to Ctrl/Cmd+Enter, while preserving regular Enter-as-newline behavior in that mode.
+
 ## [v0.51.157] — 2026-05-28 — Release EC (stage-batch39 — 5-PR mixed-risk cleanup: gateway prefill forward + prefill budget + compressed-continuation sidebar + browser-transcript memory guidance + reasoning max parity)
 
 ### Added
diff --git a/static/boot.js b/static/boot.js
index 072171b5..f507af88 100644
--- a/static/boot.js
+++ b/static/boot.js
@@ -1115,6 +1115,9 @@ function _isVirtualKeyboardLikelyOpen(){
   if(!vv||!window.innerHeight)return true;
   return window.innerHeight-vv.height>120;
 }
+function _isNumpadEnter(e){
+  return e.key==='Enter'&&(e.code==='NumpadEnter'||e.location===KeyboardEvent.DOM_KEY_LOCATION_NUMPAD);
+}
 $('msg').addEventListener('keydown',e=>{
   // Autocomplete navigation when dropdown is open
   const dd=$('cmdDropdown');
@@ -1139,9 +1142,10 @@ $('msg').addEventListener('keydown',e=>{
   // Users can override in Settings by explicitly choosing 'enter' mode.
   if(e.key==='Enter'){
     if(_isImeEnter(e)){return;}
+    const isNumpadEnter=_isNumpadEnter(e);
     const _mobileDefault=matchMedia('(pointer:coarse)').matches&&window._sendKey==='enter'&&_isVirtualKeyboardLikelyOpen();
     if(window._sendKey==='ctrl+enter'||_mobileDefault){
-      if(e.ctrlKey||e.metaKey){e.preventDefault();send();}
+      if(isNumpadEnter||e.ctrlKey||e.metaKey){e.preventDefault();send();}
     } else {
       if(!e.shiftKey){e.preventDefault();send();}
     }
diff --git a/tests/test_numpad_enter_submit.py b/tests/test_numpad_enter_submit.py
new file mode 100644
index 00000000..ac4fbcc3
--- /dev/null
+++ b/tests/test_numpad_enter_submit.py
@@ -0,0 +1,26 @@
+"""Keyboard contract for treating Numpad Enter as a submit shortcut."""
+
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parents[1]
+BOOT_JS = (REPO / "static" / "boot.js").read_text(encoding="utf-8")
+
+
+def test_boot_defines_numpad_enter_helper():
+    assert "function _isNumpadEnter(e)" in BOOT_JS
+    assert "e.code==='NumpadEnter'" in BOOT_JS
+    assert "e.location===KeyboardEvent.DOM_KEY_LOCATION_NUMPAD" in BOOT_JS
+
+
+def test_ctrl_enter_mode_allows_numpad_enter_to_submit():
+    ctrl_branch = BOOT_JS.split("if(window._sendKey==='ctrl+enter'||_mobileDefault){", 1)[1]
+    ctrl_branch = ctrl_branch.split("} else {", 1)[0]
+    assert "isNumpadEnter" in ctrl_branch
+    assert "if(isNumpadEnter||e.ctrlKey||e.metaKey){e.preventDefault();send();}" in ctrl_branch
+
+
+def test_ime_guard_runs_before_numpad_enter_detection():
+    enter_branch = BOOT_JS.split("if(e.key==='Enter'){")[-1]
+    ime_idx = enter_branch.index("if(_isImeEnter(e)){return;}")
+    numpad_idx = enter_branch.index("const isNumpadEnter=_isNumpadEnter(e);")
+    assert ime_idx < numpad_idx