diff --git a/envsetup.sh b/envsetup.sh
index e4e2ece..9670a7f 100644
--- a/envsetup.sh
+++ b/envsetup.sh
@@ -186,7 +186,7 @@
             ;;
     esac
     if [ -n "$ANDROID_EMULATOR_PREBUILTS" -a -d "$ANDROID_EMULATOR_PREBUILTS" ]; then
-        ANDROID_BUILD_PATHS=$ANDROID_BUILD_PATHS:$ANDROID_EMULATOR_PREBUILTS
+        ANDROID_BUILD_PATHS=$ANDROID_BUILD_PATHS$ANDROID_EMULATOR_PREBUILTS:
         export ANDROID_EMULATOR_PREBUILTS
     fi