diff --git a/myst_parser/mdit_to_docutils/base.py b/myst_parser/mdit_to_docutils/base.py
index 3778dd31..992cfd22 100644
--- a/myst_parser/mdit_to_docutils/base.py
+++ b/myst_parser/mdit_to_docutils/base.py
@@ -1175,7 +1175,7 @@ def render_image(self, token: SyntaxTreeNode) -> None:
 
         img_node["uri"] = destination
 
-        img_node["alt"] = self.renderInlineAsText(token.children or [])
+        img_node["alt"] = self.renderInlineAsText(token.children or []) or destination
 
         self.copy_attributes(
             token,
diff --git a/tests/test_renderers/fixtures/docutil_syntax_elements.md b/tests/test_renderers/fixtures/docutil_syntax_elements.md
index 67668bf3..a98c8b92 100644
--- a/tests/test_renderers/fixtures/docutil_syntax_elements.md
+++ b/tests/test_renderers/fixtures/docutil_syntax_elements.md
@@ -172,6 +172,15 @@ Image empty:
         <image alt="" uri="">
 .
 
+Image without alt:
+.
+![](src)
+.
+<document source="notset">
+    <paragraph>
+        <image alt="src" uri="src">
+.
+
 Image with alt and title:
 .
 ![alt](src "title")
diff --git a/tests/test_renderers/fixtures/sphinx_syntax_elements.md b/tests/test_renderers/fixtures/sphinx_syntax_elements.md
index 1f6e1fcb..e8f88276 100644
--- a/tests/test_renderers/fixtures/sphinx_syntax_elements.md
+++ b/tests/test_renderers/fixtures/sphinx_syntax_elements.md
@@ -172,6 +172,15 @@ Image empty:
         <image alt="" uri="">
 .
 
+Image without alt:
+.
+![](src)
+.
+<document source="<src>/index.md">
+    <paragraph>
+        <image alt="src" uri="src">
+.
+
 Image with alt and title:
 .
 ![alt](src "title")