diff --git a/RoihuApp/android/app/build.gradle b/RoihuApp/android/app/build.gradle
index 095f021..d1b6953 100644
--- a/RoihuApp/android/app/build.gradle
+++ b/RoihuApp/android/app/build.gradle
@@ -88,8 +88,8 @@ android {
         applicationId "com.roihuapp"
         minSdkVersion 16
         targetSdkVersion 22
-        versionCode env["CIRCLE_BUILD_NUM"].toInteger()
-        versionName "1.0." + env["CIRCLE_BUILD_NUM"]
+        versionCode env["CIRCLE_BUILD_NUM"]?.toInteger() ?: 0
+        versionName "1.0." + (env["CIRCLE_BUILD_NUM"] ?: "0")
         ndk {
             abiFilters "armeabi-v7a", "x86"
         }