diff --git a/README.md b/README.md
index 17e38b1..0d5cc88 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,19 @@
-# cadtool-extension
+# cadtools-extension
 
-cadtool-extension is an extension adding CAD tools to OpenJUMP 
+cadtool-extension adds CAD tools to OpenJUMP 
+
+## Maven build
+
+as the extension depends on Vertex-Symbols, the dependency might be needed to be downloaded before a fresh build or after `mvn clean`. if Maven complains similar to
+
+> Could not resolve dependencies for project org.openjump:cadtools-extension:jar:2.1.2: Could not find artifact com.cadplan:vertex-symbols:jar:2.2.0
+
+the simply run `mvn initialize` one time before building like
+
+```
+mvn initialize
+mvn package
+```
 
 ## Source code
 
@@ -9,7 +22,7 @@ cadtool-extension is an extension adding CAD tools to OpenJUMP
 * Line decorations, Block and Annotation tools from AdvancedTools (Giuseppe Aruta - GeoArbores Project)
 * Other enhancements have been adapted from OpenJUMP 1.10 source code
 
-## Licences
+## Licenses
 All copyright reserved under GNU version 3
 except org.openjump.advancedtools.tools.ConstrainedNClickTool which is under GNU version 2
 
diff --git a/pom.xml b/pom.xml
index bacf522..12d027d 100644
--- a/pom.xml
+++ b/pom.xml
@@ -5,7 +5,7 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>org.openjump</groupId>
   <artifactId>cadtools-extension</artifactId>
-  <version>2.1.1</version>
+  <version>2.1.2</version>
   <name>cadtools-extension</name>
   <description>CAD like tools for OpenJUMP</description>
 
@@ -38,6 +38,7 @@
       <artifactId>vertex-symbols</artifactId>
       <version>2.2.0</version>
       <scope>system</scope>
+      <!-- run `mvn initialize` to enforce download if build fails because it's missing -->
       <systemPath>${project.build.directory}/lib.vertex-symbols/vertex-symbols-2.2.0.jar</systemPath>
     </dependency>
 
@@ -57,6 +58,29 @@
       </resource>
     </resources>
     <plugins>
+      <plugin>
+        <groupId>com.googlecode.maven-download-plugin</groupId>
+        <artifactId>download-maven-plugin</artifactId>
+        <version>1.6.8</version>
+        <configuration>
+          <alwaysVerifyChecksum>true</alwaysVerifyChecksum>
+        </configuration>
+        <executions>
+          <execution>
+            <id>download vertex-symbols</id>
+            <phase>initialize</phase>
+            <goals>
+              <goal>wget</goal>
+            </goals>
+            <configuration>
+              <url>https://github.com/openjump-gis/vertex-symbols/releases/download/v2.2.0/vertex-symbols-2.2.0.zip</url>
+              <sha1>22df1e3124113909ffaeba12f93647832554c9c1</sha1>
+              <unpack>true</unpack>
+              <outputDirectory>${project.build.directory}/lib.vertex-symbols/</outputDirectory>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
       <plugin>
         <groupId>io.github.git-commit-id</groupId>
         <artifactId>git-commit-id-maven-plugin</artifactId>
@@ -82,28 +106,6 @@
           </includeOnlyProperties>
         </configuration>
       </plugin>
-      <plugin>
-        <groupId>com.googlecode.maven-download-plugin</groupId>
-        <artifactId>download-maven-plugin</artifactId>
-        <version>1.6.6</version>
-        <configuration>
-          <alwaysVerifyChecksum>true</alwaysVerifyChecksum>
-        </configuration>
-        <executions>
-          <execution>
-            <id>download vertex-symbols</id>
-            <goals>
-              <goal>wget</goal>
-            </goals>
-            <configuration>
-              <url>https://github.com/openjump-gis/vertex-symbols/releases/download/v2.2.0/vertex-symbols-2.2.0.zip</url>
-              <sha1>22df1e3124113909ffaeba12f93647832554c9c1</sha1>
-              <unpack>true</unpack>
-              <outputDirectory>${project.build.directory}/lib.vertex-symbols/</outputDirectory>
-            </configuration>
-          </execution>
-        </executions>
-      </plugin>
       <plugin>
         <groupId>net.nicoulaj.maven.plugins</groupId>
         <artifactId>checksum-maven-plugin</artifactId>