diff --git a/.travis.yml b/.travis.yml
index e0d5eb5..c96f8af 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,4 +14,5 @@ script:
     - cargo test --features trace
     - cargo test --features functions
     - cargo test --features chrono
-    - cargo test --features "backup blob chrono functions load_extension trace"
+    - cargo test --features serde_json
+    - cargo test --features "backup blob chrono functions load_extension serde_json trace"
diff --git a/appveyor.yml b/appveyor.yml
index 0d9a5f3..9b0258c 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -16,7 +16,7 @@ build: false
 
 test_script:
   - cargo test --lib --verbose
-  - cargo test --lib --features "backup blob chrono functions load_extension trace"
+  - cargo test --lib --features "backup blob chrono functions load_extension serde_json trace"
 
 cache:
   - C:\Users\appveyor\.cargo