diff --git a/CDT-commonTypes-v0_8_0.xsd b/CDT-commonTypes-v0_8_0.xsd
index c01aa03e9f6f6bb78e0a1c3a2946cfa8248d2fc0..363f9f28fd9586d0df791ccffe62903e70286cfe 100644
--- a/CDT-commonTypes-v0_8_0.xsd
+++ b/CDT-commonTypes-v0_8_0.xsd
@@ -179,7 +179,7 @@ oneM2M EXPRESSLY ADVISES ANY AND ALL USE OF OR RELIANCE UPON THIS INFORMATION PR
 		<xs:complexContent>
 			<xs:extension base="m2m:resource">
 				<xs:sequence>
-					<xs:element name="expirationTime" type="xs:dateTime" minOccurs="0" />
+					<xs:element name="expirationTime" type="xs:dateTime" />
 					<xs:element name="announceTo" type="m2m:AnyURIList" minOccurs="0" />
 					<xs:element name="announcedAttribute" minOccurs="0">
 						<xs:simpleType>
@@ -195,7 +195,7 @@ oneM2M EXPRESSLY ADVISES ANY AND ALL USE OF OR RELIANCE UPON THIS INFORMATION PR
 		<xs:complexContent>
 			<xs:extension base="m2m:resource">
 				<xs:sequence>
-					<xs:element name="expirationTime" type="xs:dateTime" minOccurs="0" />
+					<xs:element name="expirationTime" type="xs:dateTime" />
 					<xs:element name="link" type="xs:anyURI" />
 				</xs:sequence>
 			</xs:extension>
diff --git a/CDT-schedule-v0_8_0.xsd b/CDT-schedule-v0_8_0.xsd
index 7780ed13aa1892bb05dd9f7e6e8b3b3600dbd040..fb7b04a5d1a1feb892a063075faec340971995bd 100644
--- a/CDT-schedule-v0_8_0.xsd
+++ b/CDT-schedule-v0_8_0.xsd
@@ -62,7 +62,7 @@ oneM2M EXPRESSLY ADVISES ANY AND ALL USE OF OR RELIANCE UPON THIS INFORMATION PR
 				<xs:extension base="m2m:announcedSubordinateResource">
 					<xs:sequence>
 						<!-- Resource Specific Attributes -->
-						<xs:element name="scheduleElement">
+						<xs:element name="scheduleElement" minOccurs="0">
 							<xs:complexType>
 								<xs:sequence>
 									<xs:element name="timePeriod" type="m2m:eCrontabList" maxOccurs="unbounded" />