diff --git a/result/schemas/issue40_0_0 b/result/schemas/issue40_0_0
new file mode 100644
index 00000000..73c9e696
--- /dev/null
+++ b/result/schemas/issue40_0_0
@@ -0,0 +1 @@
+./test/schemas/issue40_0.xml validates
diff --git a/result/schemas/issue40_0_0.err b/result/schemas/issue40_0_0.err
new file mode 100644
index 00000000..e69de29b
diff --git a/test/schemas/issue40_0.xml b/test/schemas/issue40_0.xml
new file mode 100644
index 00000000..86cff1d0
--- /dev/null
+++ b/test/schemas/issue40_0.xml
@@ -0,0 +1,3 @@
+<a:aaa xmlns:a="aaa_ns">
+  <x/>
+</a:aaa>
diff --git a/test/schemas/issue40_0.xsd b/test/schemas/issue40_0.xsd
new file mode 100644
index 00000000..a7eff55b
--- /dev/null
+++ b/test/schemas/issue40_0.xsd
@@ -0,0 +1,10 @@
+<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" targetNamespace="aaa_ns" xmlns="http://www.w3.org/1999/XSL/Transform">
+	<xsd:element name="aaa">
+		<xsd:complexType>
+			<xsd:choice>
+				<xsd:any namespace="##other" processContents="skip" />
+				<xsd:any namespace="##local" processContents="skip" />
+			</xsd:choice>
+		</xsd:complexType>
+	</xsd:element>
+</xsd:schema>
diff --git a/xmlregexp.c b/xmlregexp.c
index 1e8bf934..10969177 100644
--- a/xmlregexp.c
+++ b/xmlregexp.c
@@ -2528,9 +2528,18 @@ xmlFACompareAtoms(xmlRegAtomPtr atom1, xmlRegAtomPtr atom2, int deep) {
         case XML_REGEXP_STRING:
             if (!deep)
                 ret = (atom1->valuep != atom2->valuep);
-            else
-                ret = xmlRegStrEqualWildcard((xmlChar *)atom1->valuep,
-                                             (xmlChar *)atom2->valuep);
+            else {
+                xmlChar *val1 = (xmlChar *)atom1->valuep;
+                xmlChar *val2 = (xmlChar *)atom2->valuep;
+                int compound1 = (xmlStrchr(val1, '|') != NULL);
+                int compound2 = (xmlStrchr(val2, '|') != NULL);
+
+                /* Ignore negative match flag for ##other namespaces */
+                if (compound1 != compound2)
+                    return(0);
+
+                ret = xmlRegStrEqualWildcard(val1, val2);
+            }
 	    break;
         case XML_REGEXP_EPSILON:
 	    goto not_determinist;