diff --git a/.circleci/config.yml b/.circleci/config.yml
index e49cc159ca..3ea9e1ab9d 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -32,7 +32,7 @@ jobs:
           command: rm -rf ~/.m2/repository/org/springframework/cloud/contract && rm -rf ~/.m2/repository/com/example
       - run:
           name: "Running build"
-          command: ./mvnw -s .settings.xml clean org.jacoco:jacoco-maven-plugin:prepare-agent install -U -Pdocs,fast,integration,sonar -nsu --batch-mode -Dmaven.test.redirectTestOutputToFile=true -Dorg.slf4j.simpleLogger.log.org.apache.maven.cli.transfer.Slf4jMavenTransferListener=warn
+          command: ./mvnw -s .settings.xml clean install -U -Pdocs,fast,integration -nsu --batch-mode -Dmaven.test.redirectTestOutputToFile=true -Dorg.slf4j.simpleLogger.log.org.apache.maven.cli.transfer.Slf4jMavenTransferListener=warn
       - run:
           name: "Aggregate test results"
           when: always
diff --git a/specs/spring-cloud-contract-spec-java/src/main/java/org/springframework/cloud/contract/spec/internal/OptionalProperty.java b/specs/spring-cloud-contract-spec-java/src/main/java/org/springframework/cloud/contract/spec/internal/OptionalProperty.java
index 6e19b1482c..bafd2ad923 100644
--- a/specs/spring-cloud-contract-spec-java/src/main/java/org/springframework/cloud/contract/spec/internal/OptionalProperty.java
+++ b/specs/spring-cloud-contract-spec-java/src/main/java/org/springframework/cloud/contract/spec/internal/OptionalProperty.java
@@ -44,8 +44,15 @@ public class OptionalProperty implements Serializable, CanBeDynamic {
 	}
 
 	public String value() {
-		return this.value instanceof RegexProperty
-				? ((RegexProperty) this.value).pattern() : this.value.toString();
+		if (this.value == null) {
+			return "";
+		}
+		else if (this.value instanceof RegexProperty) {
+			return ((RegexProperty) this.value).pattern();
+		}
+		else {
+			return this.value.toString();
+		}
 	}
 
 	protected Pattern optionalPatternValue() {
diff --git a/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/QueryParamsResolver.java b/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/QueryParamsResolver.java
index 4a58847066..461f8a45a9 100644
--- a/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/QueryParamsResolver.java
+++ b/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/QueryParamsResolver.java
@@ -34,12 +34,12 @@ interface QueryParamsResolver {
 			return resolveParamValue(((OptionalProperty) value).optionalPattern());
 		}
 		else if (value instanceof MatchingStrategy) {
-			return ((MatchingStrategy) value).getServerValue().toString();
+			return resolveParamValue(((MatchingStrategy) value).getServerValue());
 		}
 		else if (value instanceof DslProperty) {
 			return resolveParamValue(((DslProperty) value).getServerValue());
 		}
-		return value.toString();
+		return value == null ? "null" : value.toString();
 	}
 
 }
diff --git a/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/util/ContractVerifierDslConverter.groovy b/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/util/ContractVerifierDslConverter.groovy
index e2841d49d6..f5590a8159 100644
--- a/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/util/ContractVerifierDslConverter.groovy
+++ b/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/util/ContractVerifierDslConverter.groovy
@@ -128,16 +128,19 @@ class ContractVerifierDslConverter implements ContractConverter<Collection<Contr
 	private static Object toObject(ClassLoader cl, File rootFolder, File dsl) {
 		if (isJava(dsl)) {
 			try {
-				return parseJavaFile(dsl)
+				return parseJavaFile(cl, dsl)
 			}
 			catch (Exception ex) {
-				throw new DslParseException("Exception occurred while trying to parse the file [" + dsl + "] as a contract. Will not parse it.", ex)
+				if (log.isWarnEnabled()) {
+					log.warn("Exception occurred while trying to parse the file [" + dsl + "] as a contract. Will not parse it.", ex)
+				}
+				return null
 			}
 		}
 		return groovyShell(cl, rootFolder).evaluate(dsl)
 	}
 
-	private static Object parseJavaFile(File dsl) {
+	private static Object parseJavaFile(ClassLoader cl, File dsl) {
 		Constructor<?> constructor = classConstructor(dsl)
 		Object newInstance = constructor.newInstance()
 		if (!newInstance instanceof Supplier) {
@@ -158,7 +161,7 @@ class ContractVerifierDslConverter implements ContractConverter<Collection<Contr
 		if (!compilationResult.wasSuccessful()) {
 			throw new IllegalStateException("Exceptions occurred while trying to compile the file " + compilationResult.compilationMessages)
 		}
-		Class<?> clazz = compilationResult.compiledClasses.find { it.name == fqn }
+		Class<?> clazz = compilationResult.compiledClasses.find { it.name == fqn}
 		if (clazz == null) {
 			throw new IllegalStateException("Class with name [" + fqn + "] not found")
 		}
diff --git a/spring-cloud-contract-verifier/src/test/groovy/org/springframework/cloud/contract/verifier/builder/QueryParamsResolverSpec.groovy b/spring-cloud-contract-verifier/src/test/groovy/org/springframework/cloud/contract/verifier/builder/QueryParamsResolverSpec.groovy
new file mode 100644
index 0000000000..4a0fd0dba6
--- /dev/null
+++ b/spring-cloud-contract-verifier/src/test/groovy/org/springframework/cloud/contract/verifier/builder/QueryParamsResolverSpec.groovy
@@ -0,0 +1,84 @@
+package org.springframework.cloud.contract.verifier.builder
+
+import org.springframework.cloud.contract.spec.internal.DslProperty
+import org.springframework.cloud.contract.spec.internal.MatchingStrategy
+import org.springframework.cloud.contract.spec.internal.OptionalProperty
+import org.springframework.cloud.contract.spec.internal.QueryParameter
+import org.springframework.cloud.contract.spec.internal.RegexProperty
+import spock.lang.Specification
+
+import java.util.regex.Pattern
+
+class QueryParamsResolverSpec extends Specification {
+
+	def 'should return serverValue for QueryParameter'() {
+		given:
+			Object parameter = new QueryParameter("some_param", dslProperty)
+		when:
+			String resolved = new QueryParamsResolver() {}.resolveParamValue(parameter)
+		then:
+			resolved == expected
+		where:
+			dslProperty                                 | expected
+			new DslProperty<String>("client", "server") | "server"
+			new DslProperty<String>(null, "server")     | "server"
+			new DslProperty<String>("client", null)     | "null"
+			new DslProperty<String>(null, null)         | "null"
+	}
+
+	def 'should return optionalPattern for OptionalProperty'() {
+		given:
+			Object parameter = new OptionalProperty(value)
+		when:
+			String resolved = new QueryParamsResolver() {}.resolveParamValue(parameter)
+		then:
+			resolved == expected
+		where:
+			value                                          | expected
+			"server"                                       | "(server)?"
+			null                                           | "()?"
+			new RegexProperty(Pattern.compile(".*"))       | "(.*)?"
+			new RegexProperty(null, Pattern.compile(".*")) | "(.*)?"
+			new RegexProperty(Pattern.compile(".*"), null) | "(.*)?"
+			new RegexProperty("", Pattern.compile(".*"))   | "(.*)?"
+			new RegexProperty(Pattern.compile(".*"), "")   | "(.*)?"
+	}
+
+	def 'should return serverValue for MatchingStrategy'() {
+		given:
+			Object parameter = new MatchingStrategy(value, MatchingStrategy.Type.EQUAL_TO)
+		when:
+			String resolved = new QueryParamsResolver() {}.resolveParamValue(parameter)
+		then:
+			resolved == expected
+		where:
+			value                                       | expected
+			"server"                                    | "server"
+			null                                        | "null"
+			new DslProperty<String>("client", "server") | "server"
+			new DslProperty<String>(null, "server")     | "server"
+			new DslProperty<String>("client", null)     | "null"
+			new DslProperty<String>(null, null)         | "null"
+	}
+
+	def 'should return serverValue for DslProperty'() {
+		when:
+			String resolved = new QueryParamsResolver() {}.resolveParamValue(parameter)
+		then:
+			resolved == expected
+		where:
+			parameter                                   | expected
+			new DslProperty<String>("client", "server") | "server"
+			new DslProperty<String>(null, "server")     | "server"
+			new DslProperty<String>("client", null)     | "null"
+			new DslProperty<String>(null, null)         | "null"
+	}
+
+	def 'should return \"null\" for null'() {
+		when:
+			String resolved = new QueryParamsResolver() {}.resolveParamValue(null)
+		then:
+			resolved == "null"
+	}
+
+}