diff --git a/redisless/src/server/tests/mod.rs b/redisless/src/server/tests/mod.rs
index d0f9cb4..4d8a68b 100644
--- a/redisless/src/server/tests/mod.rs
+++ b/redisless/src/server/tests/mod.rs
@@ -1,6 +1,7 @@
 use redis::{Commands, Connection, RedisResult};
 use std::{thread::sleep, time::Duration};
 
+use crate::command::command_error::RedisCommandError;
 use crate::server::ServerState;
 use crate::storage::in_memory::InMemoryStorage;
 use crate::Server;
@@ -37,6 +38,15 @@ fn test_incr_decr_commands() {
     let value: u32 = con.get("63").unwrap();
     assert_eq!(value, 79_u32);
 
+    let response: Result<i64, redis::RedisError> = con.incr("63", "foo");
+    match response {
+        Ok(_) => panic!("got valid response from incr command for key {} and value {}", "63", "foo"),
+        Err(error) => {
+            assert_eq!(error.kind(), redis::ErrorKind::ExtensionError);
+            assert_eq!(error.to_string(), "invalid: digit found in string");
+        }
+    };
+
     assert_eq!(server.stop(), Some(ServerState::Stopped));
 }
 
diff --git a/redisless/src/server/util/run_command.rs b/redisless/src/server/util/run_command.rs
index 93520c2..81f245b 100644
--- a/redisless/src/server/util/run_command.rs
+++ b/redisless/src/server/util/run_command.rs
@@ -123,15 +123,14 @@ pub fn run_command_and_get_response<T: Storage>(
 
                 match storage.read(k.as_slice()) {
                     Some(value) => {
-                        if let Ok(mut int_val) = std::str::from_utf8(value).unwrap().parse::<i64>()
-                        {
-                            int_val += 1;
-                            let new_value = int_val.to_string().into_bytes();
-                            storage.write(k.as_slice(), new_value.as_slice());
-                            RedisResponse::single(Integer(int_val as i64))
-                        } else {
-                            // handle this error
-                            unimplemented!()
+                        match std::str::from_utf8(value).unwrap().parse::<i64>() {
+                            Ok(mut int_val) => {
+                                int_val += 1;
+                                let new_value = int_val.to_string().into_bytes();
+                                storage.write(k.as_slice(), new_value.as_slice());
+                                RedisResponse::single(Integer(int_val as i64))
+                            }
+                            Err(error) => RedisResponse::error(RedisCommandError::IntParse(error))
                         }
                     }
                     None => {
@@ -146,15 +145,14 @@ pub fn run_command_and_get_response<T: Storage>(
 
                 match storage.read(k.as_slice()) {
                     Some(value) => {
-                        if let Ok(mut int_val) = std::str::from_utf8(value).unwrap().parse::<i64>()
-                        {
-                            int_val += increment;
-                            let new_value = int_val.to_string().into_bytes();
-                            storage.write(k.as_slice(), new_value.as_slice());
-                            RedisResponse::single(Integer(int_val as i64))
-                        } else {
-                            //RedisResponse::error(...)
-                            unimplemented!()
+                        match std::str::from_utf8(value).unwrap().parse::<i64>() {
+                            Ok(mut int_val) => {
+                                int_val += increment;
+                                let new_value = int_val.to_string().into_bytes();
+                                storage.write(k.as_slice(), new_value.as_slice());
+                                RedisResponse::single(Integer(int_val as i64))
+                            }
+                            Err(error) => RedisResponse::error(RedisCommandError::IntParse(error))
                         }
                     }
                     None => {