diff --git a/profile/README.md b/profile/README.md
index 8804a56..50a0a55 100644
--- a/profile/README.md
+++ b/profile/README.md
@@ -29,6 +29,20 @@ Please let us know how can we improve it! Please raise GitHub Issues in the [Doc
 Contributors who have supported and advanced the BHoM.
 
 <table cellpadding="4" cellspacing="0">
+  <colgroup>
+    <col width="55"/>
+    <col width="55"/>
+    <col width="55"/>
+    <col width="55"/>
+    <col width="55"/>
+    <col width="55"/>
+    <col width="55"/>
+    <col width="55"/>
+    <col width="55"/>
+    <col width="55"/>
+    <col width="55"/>
+    <col width="55"/>
+  </colgroup>
   <tr>
     <td align="center" valign="top" width="55">
       <a href="https://github.com/polnischfrosch" title="@polnischfrosch"><img src="https://github.com/polnischfrosch.png?size=45" width="45" height="45" style="border-radius: 50%" /><br/><sub><b>AaronWagner</b></sub></a>
diff --git a/scripts/generate_wall_of_honour.py b/scripts/generate_wall_of_honour.py
index e18a259..4c200ae 100644
--- a/scripts/generate_wall_of_honour.py
+++ b/scripts/generate_wall_of_honour.py
@@ -138,12 +138,16 @@ def render_wall(
     else:
         stats = f"{contributors_part}. Last updated {last_updated}."
 
+    colgroup_lines = "\n".join(f"    <col width=\"{CELL_WIDTH}\"/>" for _ in range(GRID_COLS))
+    colgroup = "  <colgroup>\n" + colgroup_lines + "\n  </colgroup>"
+
     return (
         "<!-- WALL:START -->\n\n"
         "---\n\n"
         "<div align=\"center\">\n\n"
         f"{INTRO_TEXT}\n\n"
         "<table cellpadding=\"4\" cellspacing=\"0\">\n"
+        + colgroup + "\n"
         + "\n".join(rows)
         + "\n</table>\n\n"
         f"{stats}\n\n"
diff --git a/scripts/tests/test_generate.py b/scripts/tests/test_generate.py
index 0059e12..b623740 100644
--- a/scripts/tests/test_generate.py
+++ b/scripts/tests/test_generate.py
@@ -293,6 +293,15 @@ def test_render_wall_uses_valign_top():
     assert "valign=\"top\"" in md
 
 
+def test_render_wall_uses_colgroup_for_uniform_column_widths():
+    # colgroup gives GitHub's table renderer authoritative column widths,
+    # preventing content-based auto-sizing that produces uneven cell widths.
+    contributors = {"alice": {"avatar_url": "x", "contributions": 1, "name": "Alice"}}
+    md = render_wall(contributors, "2026-06-08")
+    assert "<colgroup>" in md
+    assert md.count("<col width=\"55\"/>") == 12  # one <col> per GRID_COLS
+
+
 def test_render_wall_sort_is_case_insensitive_and_unicode():
     contributors = {
         "zoe": {"avatar_url": "z", "contributions": 1, "name": "Zoe"},