diff --git a/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/ComparisonBuilder.java b/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/ComparisonBuilder.java
index 5e4dc89d68..59b44594cb 100644
--- a/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/ComparisonBuilder.java
+++ b/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/ComparisonBuilder.java
@@ -74,7 +74,9 @@ interface ComparisonBuilder {
 	}
 
 	default String isEqualTo(Number number) {
-		return ".isEqualTo(" + number.toString() + ")";
+		String numberString = number instanceof Long ? number.toString() + "L"
+				: number.toString();
+		return ".isEqualTo(" + numberString + ")";
 	}
 
 	default String isNotNull() {
diff --git a/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/GroovyComparisonBuilder.java b/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/GroovyComparisonBuilder.java
index 7e2f63f74e..4b132e6fc4 100644
--- a/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/GroovyComparisonBuilder.java
+++ b/spring-cloud-contract-verifier/src/main/groovy/org/springframework/cloud/contract/verifier/builder/GroovyComparisonBuilder.java
@@ -40,7 +40,9 @@ interface GroovyComparisonBuilder extends ComparisonBuilder {
 
 	@Override
 	default String isEqualTo(Number number) {
-		return " == " + number.toString();
+		String numberString = number instanceof Long ? number.toString() + "L"
+				: number.toString();
+		return " == " + numberString;
 	}
 
 	@Override
diff --git a/spring-cloud-contract-verifier/src/test/groovy/org/springframework/cloud/contract/verifier/builder/SpringTestMethodBodyBuildersSpec.groovy b/spring-cloud-contract-verifier/src/test/groovy/org/springframework/cloud/contract/verifier/builder/SpringTestMethodBodyBuildersSpec.groovy
index 9373c37594..fc34132784 100644
--- a/spring-cloud-contract-verifier/src/test/groovy/org/springframework/cloud/contract/verifier/builder/SpringTestMethodBodyBuildersSpec.groovy
+++ b/spring-cloud-contract-verifier/src/test/groovy/org/springframework/cloud/contract/verifier/builder/SpringTestMethodBodyBuildersSpec.groovy
@@ -3130,4 +3130,35 @@ DocumentContext parsedJson = JsonPath.parse(json);
 			}
 			"webclient"       | { properties.testMode = TestMode.WEBTESTCLIENT }
 	}
+
+	@Issue('#1052')
+	def 'should work with large numbers [#methodBuilderName]'() {
+		given:
+			Contract contractDsl = Contract.make {
+				label 'storage_object_created'
+				input {
+					triggeredBy('toString()')
+				}
+
+				outputMessage {
+					sentTo('document_uploads')
+					headers {
+						header('objectGeneration', 23094823904823)
+					}
+				}
+			}
+			methodBuilder()
+		when:
+			String test = singleTestGenerator(contractDsl)
+		then:
+			SyntaxChecker.tryToCompile(methodBuilderName, test)
+		and:
+			test.contains('''23094823904823L''')
+		where:
+			methodBuilderName | methodBuilder
+			"spock"           | { properties.testFramework = TestFramework.SPOCK }
+			"testng"          | { properties.testFramework = TestFramework.TESTNG }
+			"junit"           | { properties.testFramework = TestFramework.JUNIT }
+			"junit5"          | { properties.testFramework = TestFramework.JUNIT5 }
+	}
 }