diff --git a/Cargo.toml b/Cargo.toml
index 2db1078..bf9a231 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -49,14 +49,15 @@ rand = { version = "0.6", features = ["wasm-bindgen"] }
 
 [[example]]
 name = "sign_verify_recovery"
-required-features = ["recovery"]
+required-features = ["std", "recovery"]
 
 [[example]]
 name = "sign_verify"
+required-features = ["std"]
 
 [[example]]
 name = "generate_keys"
-required-features = ["rand"]
+required-features = ["std", "rand-std"]
 
 [workspace]
 members = ["secp256k1-sys"]
diff --git a/contrib/test.sh b/contrib/test.sh
index dc936ab..d1cd935 100755
--- a/contrib/test.sh
+++ b/contrib/test.sh
@@ -45,9 +45,9 @@ if [ "$DO_FEATURE_MATRIX" = true ]; then
     fi
 
     # Examples
-    cargo run --example sign_verify
-    cargo run --example sign_verify_recovery --features=recovery
-    cargo run --example generate_keys --features=rand
+    cargo run --example sign_verify --features=std
+    cargo run --example sign_verify_recovery --features=std,recovery
+    cargo run --example generate_keys --features=std,rand-std
 fi
 
 # Docs