diff --git a/markdownify/__init__.py b/markdownify/__init__.py
index ac34ee5..7f69bfe 100644
--- a/markdownify/__init__.py
+++ b/markdownify/__init__.py
@@ -701,6 +701,12 @@ class MarkdownConverter(object):
         )
         overline = ''
         underline = ''
+        full_colspan = 0
+        for cell in cells:
+            if 'colspan' in cell.attrs and cell['colspan'].isdigit():
+                full_colspan += int(cell["colspan"])
+            else:
+                full_colspan += 1
         if ((is_headrow
              or (is_head_row_missing
                  and self.options['table_infer_header']))
@@ -709,12 +715,6 @@ class MarkdownConverter(object):
             # - is headline or
             # - headline is missing and header inference is enabled
             # print headline underline
-            full_colspan = 0
-            for cell in cells:
-                if 'colspan' in cell.attrs and cell['colspan'].isdigit():
-                    full_colspan += int(cell["colspan"])
-                else:
-                    full_colspan += 1
             underline += '| ' + ' | '.join(['---'] * full_colspan) + ' |' + '\n'
         elif ((is_head_row_missing
                and not self.options['table_infer_header'])
@@ -727,8 +727,8 @@ class MarkdownConverter(object):
             #  - the parent is table or
             #  - the parent is tbody at the beginning of a table.
             # print empty headline above this row
-            overline += '| ' + ' | '.join([''] * len(cells)) + ' |' + '\n'
-            overline += '| ' + ' | '.join(['---'] * len(cells)) + ' |' + '\n'
+            overline += '| ' + ' | '.join([''] * full_colspan) + ' |' + '\n'
+            overline += '| ' + ' | '.join(['---'] * full_colspan) + ' |' + '\n'
         return overline + '|' + text + '\n' + underline
 
 
diff --git a/tests/test_tables.py b/tests/test_tables.py
index e41b389..7e0670c 100644
--- a/tests/test_tables.py
+++ b/tests/test_tables.py
@@ -267,6 +267,23 @@ table_with_undefined_colspan = """<table>
     </tr>
 </table>"""
 
+table_with_colspan_missing_head = """<table>
+    <tr>
+        <td colspan="2">Name</td>
+        <td>Age</td>
+    </tr>
+    <tr>
+        <td>Jill</td>
+        <td>Smith</td>
+        <td>50</td>
+    </tr>
+    <tr>
+        <td>Eve</td>
+        <td>Jackson</td>
+        <td>94</td>
+    </tr>
+</table>"""
+
 
 def test_table():
     assert md(table) == '\n\n| Firstname | Lastname | Age |\n| --- | --- | --- |\n| Jill | Smith | 50 |\n| Eve | Jackson | 94 |\n\n'
@@ -283,6 +300,7 @@ def test_table():
     assert md(table_with_caption) == 'TEXT\n\nCaption\n\n|  |  |  |\n| --- | --- | --- |\n| Firstname | Lastname | Age |\n\n'
     assert md(table_with_colspan) == '\n\n| Name | | Age |\n| --- | --- | --- |\n| Jill | Smith | 50 |\n| Eve | Jackson | 94 |\n\n'
     assert md(table_with_undefined_colspan) == '\n\n| Name | Age |\n| --- | --- |\n| Jill | Smith |\n\n'
+    assert md(table_with_colspan_missing_head) == '\n\n|  |  |  |\n| --- | --- | --- |\n| Name | | Age |\n| Jill | Smith | 50 |\n| Eve | Jackson | 94 |\n\n'
 
 
 def test_table_infer_header():
@@ -300,3 +318,4 @@ def test_table_infer_header():
     assert md(table_with_caption, table_infer_header=True) == 'TEXT\n\nCaption\n\n| Firstname | Lastname | Age |\n| --- | --- | --- |\n\n'
     assert md(table_with_colspan, table_infer_header=True) == '\n\n| Name | | Age |\n| --- | --- | --- |\n| Jill | Smith | 50 |\n| Eve | Jackson | 94 |\n\n'
     assert md(table_with_undefined_colspan, table_infer_header=True) == '\n\n| Name | Age |\n| --- | --- |\n| Jill | Smith |\n\n'
+    assert md(table_with_colspan_missing_head, table_infer_header=True) == '\n\n| Name | | Age |\n| --- | --- | --- |\n| Jill | Smith | 50 |\n| Eve | Jackson | 94 |\n\n'