wrong versioning

pom.xml

@@ -10,7 +10,7 @@
 		<maven.compiler.target>1.8</maven.compiler.target>
 		<maven.compiler.source>1.8</maven.compiler.source>
 		<tycho.version>1.4.0</tycho.version>
-		<tycho-extras-version>1.4.0</tycho-extras-version>
+		<tycho.extras.version>1.4.0</tycho.extras.version>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 		<p2.repo>http://download.eclipse.org/releases/oxygen</p2.repo>
 	</properties>
@@ -145,22 +145,22 @@
 				<plugin>
 					<groupId>org.eclipse.tycho</groupId>
 					<artifactId>tycho-p2-plugin</artifactId>
-					<version>${tycho-version}</version>
+					<version>${tycho.version}</version>
 				</plugin>
 				<plugin>
 					<groupId>org.eclipse.tycho</groupId>
 					<artifactId>target-platform-configuration</artifactId>
-					<version>${tycho-version}</version>
+					<version>${tycho.version}</version>
 				</plugin>
 				<plugin>
 					<groupId>org.eclipse.tycho.extras</groupId>
 					<artifactId>tycho-pack200a-plugin</artifactId>
-					<version>${tycho-extras-version}</version>
+					<version>${tycho.extras.version}</version>
 				</plugin>
 				<plugin>
 					<groupId>org.eclipse.tycho.extras</groupId>
 					<artifactId>tycho-pack200b-plugin</artifactId>
-					<version>${tycho-extras-version}</version>
+					<version>${tycho.extras.version}</version>
 				</plugin>
 				<plugin>
 					<groupId>org.eclipse.cbi.maven.plugins</groupId>