diff --git a/echo-core/src/main/java/com/netflix/spinnaker/echo/build/BuildInfoService.java b/echo-core/src/main/java/com/netflix/spinnaker/echo/build/BuildInfoService.java
index 608d0a640..e8e5ec967 100644
--- a/echo-core/src/main/java/com/netflix/spinnaker/echo/build/BuildInfoService.java
+++ b/echo-core/src/main/java/com/netflix/spinnaker/echo/build/BuildInfoService.java
@@ -48,7 +48,7 @@ public class BuildInfoService {
   // to pass a trigger and
   // an event as with other triggers, but for now we'll see whether we can extract a build event
   // from the trigger.
-  public BuildEvent getBuildEvent(String master, String job, int buildNumber) {
+  public BuildEvent getBuildEvent(String master, String job, String buildNumber) {
     Map<String, Object> rawBuild = retry(() -> igorService.getBuild(buildNumber, master, job));
     BuildEvent.Build build = objectMapper.convertValue(rawBuild, BuildEvent.Build.class);
     BuildEvent.Project project = new BuildEvent.Project(job, build);
@@ -61,7 +61,7 @@ public BuildEvent getBuildEvent(String master, String job, int buildNumber) {
   public Map<String, Object> getBuildInfo(BuildEvent event) {
     String master = event.getContent().getMaster();
     String job = event.getContent().getProject().getName();
-    int buildNumber = event.getBuildNumber();
+    String buildNumber = event.getBuildNumber();
 
     if (StringUtils.isNoneEmpty(master, job)) {
       return retry(() -> igorService.getBuild(buildNumber, master, job));
@@ -72,7 +72,7 @@ public Map<String, Object> getBuildInfo(BuildEvent event) {
   public Map<String, Object> getProperties(BuildEvent event, String propertyFile) {
     String master = event.getContent().getMaster();
     String job = event.getContent().getProject().getName();
-    int buildNumber = event.getBuildNumber();
+    String buildNumber = event.getBuildNumber();
 
     if (StringUtils.isEmpty(propertyFile) && master.contains("travis")) {
       propertyFile = "travis";
@@ -87,7 +87,7 @@ public Map<String, Object> getProperties(BuildEvent event, String propertyFile)
   private List<Artifact> getArtifactsFromPropertyFile(BuildEvent event, String propertyFile) {
     String master = event.getContent().getMaster();
     String job = event.getContent().getProject().getName();
-    int buildNumber = event.getBuildNumber();
+    String buildNumber = event.getBuildNumber();
     if (StringUtils.isNoneEmpty(master, job, propertyFile)) {
       return retry(() -> igorService.getArtifacts(buildNumber, propertyFile, master, job));
     }
diff --git a/echo-core/src/main/java/com/netflix/spinnaker/echo/services/IgorService.java b/echo-core/src/main/java/com/netflix/spinnaker/echo/services/IgorService.java
index b5939075e..6837b5c2d 100644
--- a/echo-core/src/main/java/com/netflix/spinnaker/echo/services/IgorService.java
+++ b/echo-core/src/main/java/com/netflix/spinnaker/echo/services/IgorService.java
@@ -26,20 +26,20 @@
 public interface IgorService {
   @GET("/builds/status/{buildNumber}/{master}/{job}")
   Map<String, Object> getBuild(
-      @Path("buildNumber") Integer buildNumber,
+      @Path("buildNumber") String buildNumber,
       @Path("master") String master,
       @Path(value = "job", encode = false) String job);
 
   @GET("/builds/properties/{buildNumber}/{fileName}/{master}/{job}")
   Map<String, Object> getPropertyFile(
-      @Path("buildNumber") Integer buildNumber,
+      @Path("buildNumber") String buildNumber,
       @Path("fileName") String fileName,
       @Path("master") String master,
       @Path(value = "job", encode = false) String job);
 
   @GET("/builds/artifacts/{buildNumber}/{master}/{job}")
   List<Artifact> getArtifacts(
-      @Path("buildNumber") Integer buildNumber,
+      @Path("buildNumber") String buildNumber,
       @Query("propertyFile") String propertyFile,
       @Path("master") String master,
       @Path(value = "job", encode = false) String job);
diff --git a/echo-model/src/main/java/com/netflix/spinnaker/echo/model/Trigger.java b/echo-model/src/main/java/com/netflix/spinnaker/echo/model/Trigger.java
index 051e1fdb6..d4f1a38be 100644
--- a/echo-model/src/main/java/com/netflix/spinnaker/echo/model/Trigger.java
+++ b/echo-model/src/main/java/com/netflix/spinnaker/echo/model/Trigger.java
@@ -178,7 +178,7 @@ public String toString() {
   String artifactName;
 
   /** Properties that are bound at run-time */
-  Integer buildNumber;
+  String buildNumber;
 
   String hash;
   Map<String, Object> buildInfo;
@@ -217,7 +217,7 @@ public String generateFallbackId() {
     return UUID.nameUUIDFromBytes(this.toString().getBytes()).toString();
   }
 
-  public Trigger atBuildNumber(final int buildNumber) {
+  public Trigger atBuildNumber(final String buildNumber) {
     return this.toBuilder().buildNumber(buildNumber).hash(null).tag(null).build();
   }
 
diff --git a/echo-model/src/main/java/com/netflix/spinnaker/echo/model/trigger/BuildEvent.java b/echo-model/src/main/java/com/netflix/spinnaker/echo/model/trigger/BuildEvent.java
index 139226b80..c1e2f076a 100644
--- a/echo-model/src/main/java/com/netflix/spinnaker/echo/model/trigger/BuildEvent.java
+++ b/echo-model/src/main/java/com/netflix/spinnaker/echo/model/trigger/BuildEvent.java
@@ -57,7 +57,7 @@ public static class Project {
   @JsonIgnoreProperties(ignoreUnknown = true)
   public static class Build {
     private boolean building;
-    private int number;
+    private String number;
     private Result result;
     private String url;
     private List<Artifact> artifacts;
@@ -73,7 +73,7 @@ public enum Result {
   }
 
   @JsonIgnore
-  public int getBuildNumber() {
+  public String getBuildNumber() {
     return content.getProject().getLastBuild().getNumber();
   }
 }
diff --git a/echo-pipelinetriggers/src/main/java/com/netflix/spinnaker/echo/pipelinetriggers/eventhandlers/ManualEventHandler.java b/echo-pipelinetriggers/src/main/java/com/netflix/spinnaker/echo/pipelinetriggers/eventhandlers/ManualEventHandler.java
index c6521a760..d5c23c409 100644
--- a/echo-pipelinetriggers/src/main/java/com/netflix/spinnaker/echo/pipelinetriggers/eventhandlers/ManualEventHandler.java
+++ b/echo-pipelinetriggers/src/main/java/com/netflix/spinnaker/echo/pipelinetriggers/eventhandlers/ManualEventHandler.java
@@ -129,7 +129,7 @@ protected Pipeline buildTrigger(Pipeline pipeline, Trigger manualTrigger) {
     List<Artifact> artifacts = new ArrayList<>();
     String master = manualTrigger.getMaster();
     String job = manualTrigger.getJob();
-    Integer buildNumber = manualTrigger.getBuildNumber();
+    String buildNumber = manualTrigger.getBuildNumber();
 
     ArrayList<String> pipelineErrors = new ArrayList<>();
 
diff --git a/echo-pipelinetriggers/src/test/groovy/com/netflix/spinnaker/echo/pipelinetriggers/eventhandlers/BuildEventHandlerSpec.groovy b/echo-pipelinetriggers/src/test/groovy/com/netflix/spinnaker/echo/pipelinetriggers/eventhandlers/BuildEventHandlerSpec.groovy
index 7f04a071f..3cfc19c3e 100644
--- a/echo-pipelinetriggers/src/test/groovy/com/netflix/spinnaker/echo/pipelinetriggers/eventhandlers/BuildEventHandlerSpec.groovy
+++ b/echo-pipelinetriggers/src/test/groovy/com/netflix/spinnaker/echo/pipelinetriggers/eventhandlers/BuildEventHandlerSpec.groovy
@@ -26,7 +26,7 @@ class BuildEventHandlerSpec extends Specification implements RetrofitStubs {
 
   String MASTER_NAME = "jenkins-server"
   String JOB_NAME = "my-job"
-  int BUILD_NUMBER = 7
+  String BUILD_NUMBER = "7"
   def PROPERTY_FILE = "property-file"
   static Map<String, Object> BUILD_INFO = [
     abc: 123
diff --git a/echo-pipelinetriggers/src/test/groovy/com/netflix/spinnaker/echo/pipelinetriggers/postprocessors/ExpectedArtifactExpressionEvaluationPostProcessorSpec.groovy b/echo-pipelinetriggers/src/test/groovy/com/netflix/spinnaker/echo/pipelinetriggers/postprocessors/ExpectedArtifactExpressionEvaluationPostProcessorSpec.groovy
index d7b5b017e..08a4c6b60 100644
--- a/echo-pipelinetriggers/src/test/groovy/com/netflix/spinnaker/echo/pipelinetriggers/postprocessors/ExpectedArtifactExpressionEvaluationPostProcessorSpec.groovy
+++ b/echo-pipelinetriggers/src/test/groovy/com/netflix/spinnaker/echo/pipelinetriggers/postprocessors/ExpectedArtifactExpressionEvaluationPostProcessorSpec.groovy
@@ -19,7 +19,7 @@ class ExpectedArtifactExpressionEvaluationPostProcessorSpec extends Specificatio
     .enabled(true).type('jenkins')
     .master('master')
     .job('job')
-    .buildNumber(100)
+    .buildNumber('100')
     .build()
 
   def 'evaluates expressions in expected artifacts'() {
diff --git a/echo-test/src/main/groovy/com/netflix/spinnaker/echo/test/RetrofitStubs.groovy b/echo-test/src/main/groovy/com/netflix/spinnaker/echo/test/RetrofitStubs.groovy
index 4fadd634f..47f52b948 100644
--- a/echo-test/src/main/groovy/com/netflix/spinnaker/echo/test/RetrofitStubs.groovy
+++ b/echo-test/src/main/groovy/com/netflix/spinnaker/echo/test/RetrofitStubs.groovy
@@ -64,7 +64,7 @@ trait RetrofitStubs {
   }
 
   BuildEvent createBuildEventWith(BuildEvent.Result result) {
-    def build = result ? new BuildEvent.Build(result == BUILDING, 1, result, null, []) : null
+    def build = result ? new BuildEvent.Build(result == BUILDING, '1', result, null, []) : null
     def res = new BuildEvent()
     res.content = new BuildEvent.Content(new BuildEvent.Project("job", build), "master")
     res.details = new Metadata([type: BuildEvent.TYPE])