diff --git a/japicmp-maven-plugin/src/main/java/japicmp/maven/JApiCmpMojo.java b/japicmp-maven-plugin/src/main/java/japicmp/maven/JApiCmpMojo.java
index 7cd5ad1de..39f21e3b0 100644
--- a/japicmp-maven-plugin/src/main/java/japicmp/maven/JApiCmpMojo.java
+++ b/japicmp-maven-plugin/src/main/java/japicmp/maven/JApiCmpMojo.java
@@ -411,6 +411,7 @@ private void populateArchivesListsFromParameters(PluginParameters pluginParamete
 				throw new MojoFailureException(message);
 			}
 		}
+        getLog().debug("oldArchives=" + oldArchives + " newArchives=" + newArchives);
 	}
 
 	void breakBuildIfNecessary(List<JApiClass> jApiClasses, Parameter parameterParam, Options options, JarArchiveComparator jarArchiveComparator) throws MojoFailureException, MojoExecutionException {
@@ -657,6 +658,7 @@ private void setUpClassPath(JarArchiveComparatorOptions comparatorOptions, Plugi
 						"separate classpath for the new and old version.");
 				} else {
 					if (getLog().isDebugEnabled()) {
+                        // TODO should perhaps still use TWO_SEPARATE_CLASSPATHS and add dependencies to both?
 						getLog().debug("Element <dependencies/> found. Using " + JApiCli.ClassPathMode.ONE_COMMON_CLASSPATH);
 					}
 					for (Dependency dependency : pluginParameters.getDependenciesParam()) {
@@ -691,18 +693,41 @@ private void setUpClassPath(JarArchiveComparatorOptions comparatorOptions, Plugi
 					comparatorOptions.setClassPathMode(JarArchiveComparatorOptions.ClassPathMode.TWO_SEPARATE_CLASSPATHS);
 				} else {
 					if (getLog().isDebugEnabled()) {
-						getLog().debug("None of the elements <oldClassPathDependencies/>, <newClassPathDependencies/> or <dependencies/> found. Using " + JApiCli.ClassPathMode.ONE_COMMON_CLASSPATH);
+						getLog().debug("None of the elements <oldClassPathDependencies/>, <newClassPathDependencies/> or <dependencies/> found. Using " + JApiCli.ClassPathMode.TWO_SEPARATE_CLASSPATHS);
 					}
-					comparatorOptions.setClassPathMode(JarArchiveComparatorOptions.ClassPathMode.ONE_COMMON_CLASSPATH);
+					comparatorOptions.setClassPathMode(JarArchiveComparatorOptions.ClassPathMode.TWO_SEPARATE_CLASSPATHS);
 				}
 			}
 		}
 		setUpClassPathUsingMavenProject(comparatorOptions, mavenParameters, pluginParameters, ConfigurationVersion.NEW);
+        getLog().debug("mode=" + comparatorOptions.getClassPathMode() + " classPathEntries=" + comparatorOptions.getClassPathEntries() + " oldClassPath=" + comparatorOptions.getOldClassPath() + " newClassPath=" + comparatorOptions.getNewClassPath());
 	}
 
 	private void setUpClassPathUsingMavenProject(JarArchiveComparatorOptions comparatorOptions, MavenParameters mavenParameters, PluginParameters pluginParameters, ConfigurationVersion configurationVersion) throws MojoFailureException {
+        List<String> newClassPath;
+        if (comparatorOptions.getClassPathMode() == JarArchiveComparatorOptions.ClassPathMode.TWO_SEPARATE_CLASSPATHS) {
+            if (pluginParameters.getOldVersionParam() == null && pluginParameters.getOldVersionsParam() == null) {
+                try {
+                    // TODO rather than calling getComparisonArtifact again, populateArchivesListsFromParameters should compute the old CP for various modes
+                    Artifact comparisonArtifact = getComparisonArtifact(mavenParameters, pluginParameters);
+                    if (comparisonArtifact.getVersion() != null) {
+                        Set<Artifact> artifacts = resolveArtifact(comparisonArtifact, mavenParameters, true, pluginParameters, ConfigurationVersion.OLD);
+                        setUpClassPathEntries(artifacts, comparatorOptions.getOldClassPath(), mavenParameters, pluginParameters, configurationVersion);
+                    }
+                } catch (MojoExecutionException e) {
+                    throw new MojoFailureException("Computing and resolving comparison artifact failed: " + e.getMessage(), e);
+                }
+            }
+            newClassPath = comparatorOptions.getNewClassPath();
+        } else {
+            newClassPath = comparatorOptions.getClassPathEntries();
+        }
 		notNull(mavenParameters.getMavenProject(), "Maven parameter mavenProject should be provided by maven container.");
 		Set<Artifact> dependencyArtifacts = mavenParameters.getMavenProject().getArtifacts();
+        setUpClassPathEntries(dependencyArtifacts, newClassPath, mavenParameters, pluginParameters, configurationVersion);
+	}
+
+    private void setUpClassPathEntries(Set<Artifact> dependencyArtifacts, List<String> classPath, MavenParameters mavenParameters, PluginParameters pluginParameters, ConfigurationVersion configurationVersion) throws MojoFailureException {
 		Set<String> classPathEntries = new HashSet<>();
 		for (Artifact artifact : dependencyArtifacts) {
 			String scope = artifact.getScope();
@@ -724,10 +749,8 @@ private void setUpClassPathUsingMavenProject(JarArchiveComparatorOptions compara
 				}
 			}
 		}
-		for (String classPathEntry : classPathEntries) {
-			comparatorOptions.getClassPathEntries().add(classPathEntry);
-		}
-	}
+        classPath.addAll(classPathEntries);
+    }
 
 	private void handleMissingArtifactFile(PluginParameters pluginParameters, Artifact artifact) {
 		if (artifact.isOptional()) {
diff --git a/japicmp/src/main/java/japicmp/cmp/JApiCmpArchive.java b/japicmp/src/main/java/japicmp/cmp/JApiCmpArchive.java
index 5821058b1..ff13da264 100644
--- a/japicmp/src/main/java/japicmp/cmp/JApiCmpArchive.java
+++ b/japicmp/src/main/java/japicmp/cmp/JApiCmpArchive.java
@@ -20,4 +20,10 @@ public File getFile() {
 	public Version getVersion() {
 		return version;
 	}
+
+    @Override
+    public String toString() {
+        return file + "@" + version.getStringVersion();
+    }
+
 }