diff --git a/all/build.gradle b/all/build.gradle
index 90ec11aebd..c376fae0a8 100644
--- a/all/build.gradle
+++ b/all/build.gradle
@@ -50,7 +50,9 @@ javadoc {
 
 task jacocoMerge(type: JacocoMerge) {
     dependsOn(subprojects.jacocoTestReport.dependsOn)
+    dependsOn(project(':grpc-interop-testing').jacocoTestReport.dependsOn)
     mustRunAfter(subprojects.jacocoTestReport.mustRunAfter)
+    mustRunAfter(project(':grpc-interop-testing').jacocoTestReport.mustRunAfter)
     destinationFile = file("${buildDir}/jacoco/test.exec")
     executionData = files(subprojects.jacocoTestReport.executionData)
             .plus(project(':grpc-interop-testing').jacocoTestReport.executionData)