diff --git a/.drone.yml b/.drone.yml
index 19d24fd..7d694cf 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -31,8 +31,9 @@ steps:
   - cargo clippy --features opentelemetry_0_18 -- -D warnings
   - cargo clippy --features opentelemetry_0_19 -- -D warnings
   - cargo clippy --features opentelemetry_0_20 -- -D warnings
-  - cargo clippy --example client --features opentelemetry_0_20 -- -D warnings
-  - cargo clippy --example server --features opentelemetry_0_20 -- -D warnings
+  - cargo clippy --features opentelemetry_0_21 -- -D warnings
+  - cargo clippy --example client --features opentelemetry_0_21 -- -D warnings
+  - cargo clippy --example server --features opentelemetry_0_21 -- -D warnings
 
 trigger:
   event:
@@ -99,8 +100,8 @@ steps:
   pull: always
   commands:
   - cargo check --target=$TARGET
-  - cargo check --target=$TARGET --example client --features opentelemetry_0_20
-  - cargo check --target=$TARGET --example server --features opentelemetry_0_20
+  - cargo check --target=$TARGET --example client --features opentelemetry_0_21
+  - cargo check --target=$TARGET --example server --features opentelemetry_0_21
 
 trigger:
   event:
@@ -133,8 +134,8 @@ steps:
   pull: always
   commands:
   - cargo check --target=$TARGET
-  - cargo check --target=$TARGET --example client --features opentelemetry_0_20
-  - cargo check --target=$TARGET --example server --features opentelemetry_0_20
+  - cargo check --target=$TARGET --example client --features opentelemetry_0_21
+  - cargo check --target=$TARGET --example server --features opentelemetry_0_21
 
 trigger:
   event:
@@ -167,8 +168,8 @@ steps:
   pull: always
   commands:
   - cargo check --target=$TARGET
-  - cargo check --target=$TARGET --example client --features opentelemetry_0_20
-  - cargo check --target=$TARGET --example server --features opentelemetry_0_20
+  - cargo check --target=$TARGET --example client --features opentelemetry_0_21
+  - cargo check --target=$TARGET --example server --features opentelemetry_0_21
 
 trigger:
   event:
@@ -200,8 +201,8 @@ steps:
   pull: always
   commands:
   - cargo build --target=$TARGET
-  - cargo build --target=$TARGET --example client --features opentelemetry_0_20
-  - cargo build --target=$TARGET --example server --features opentelemetry_0_20
+  - cargo build --target=$TARGET --example client --features opentelemetry_0_21
+  - cargo build --target=$TARGET --example server --features opentelemetry_0_21
 
 trigger:
   event:
@@ -233,8 +234,8 @@ steps:
   pull: always
   commands:
   - cargo build --target=$TARGET
-  - cargo build --target=$TARGET --example client --features opentelemetry_0_20
-  - cargo build --target=$TARGET --example server --features opentelemetry_0_20
+  - cargo build --target=$TARGET --example client --features opentelemetry_0_21
+  - cargo build --target=$TARGET --example server --features opentelemetry_0_21
 
 trigger:
   event:
@@ -266,8 +267,8 @@ steps:
   pull: always
   commands:
   - cargo build --target=$TARGET
-  - cargo build --target=$TARGET --example client --features opentelemetry_0_20
-  - cargo build --target=$TARGET --example server --features opentelemetry_0_20
+  - cargo build --target=$TARGET --example client --features opentelemetry_0_21
+  - cargo build --target=$TARGET --example server --features opentelemetry_0_21
 
 trigger:
   event: