Dependency management problem

poms.xml

<!-- Parent POM -->
<!-- Spring -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>${spring.version}</version>
    <scope>compile</scope>
</dependency>

<!-- child POM -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
</dependency>

<!-- ERROR:
     [ERROR]     'dependencies.dependency.version' for org.springframework:spring-context:jar is missing. @ line 38, column 21
-->