diff --git a/eo-parser/src/main/resources/XMIR.xsd b/eo-parser/src/main/resources/XMIR.xsd
index fa908b7e12e..c7555d57009 100644
--- a/eo-parser/src/main/resources/XMIR.xsd
+++ b/eo-parser/src/main/resources/XMIR.xsd
@@ -96,7 +96,7 @@ SOFTWARE.
       </xs:documentation>
     </xs:annotation>
     <xs:restriction base="xs:string">
-      <xs:pattern value="∅|\.(^|@|[a-z]\S*)|(Q|$)(\.(^|@|[a-z]\S*))*"/>
+      <xs:pattern value="∅|\.(\^|@|[a-z][^\s.]*|α[0-9]*)|([Q$])(\.(\^|@|[a-z][^\s.]*|α[0-9]*))*"/>
     </xs:restriction>
   </xs:simpleType>
   <xs:simpleType name="program-name">
diff --git a/eo-parser/src/test/resources/org/eolang/parser/xsd-mistakes/composite-method.yaml b/eo-parser/src/test/resources/org/eolang/parser/xsd-mistakes/composite-method.yaml
new file mode 100644
index 00000000000..eb4e4581fdf
--- /dev/null
+++ b/eo-parser/src/test/resources/org/eolang/parser/xsd-mistakes/composite-method.yaml
@@ -0,0 +1,31 @@
+# The MIT License (MIT)
+#
+# Copyright (c) 2016-2025 Objectionary.com
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+---
+errors: 2
+document: |
+  <program name='foo'>
+    <objects>
+      <o base=".org.eolang">
+        <o base="Q.com"/>
+      </o>
+    </objects>
+  </program>