diff --git a/const.go b/const.go
index 8d32fa2..5128c56 100644
--- a/const.go
+++ b/const.go
@@ -18,3 +18,14 @@ const (
 	OperationPatch  = "PATCH"
 	OperationDelete = "DELETE"
 )
+
+const (
+	unknownLimiterRoleError      = "unknown limiter role operation"
+	unknownLimiterError          = "unknown limiter operation"
+	unsupportedOperationError    = "unsupported operation"
+	requiredNameDestinationError = "name and destination is required"
+	requiredLimiterIDError       = "limiter id is required"
+	createProxyError             = "Error creating proxy request"
+	sendingProxyError            = "Error sending proxy request"
+	slowDownError                = "slow down"
+)
diff --git a/golim.go b/golim.go
index 9e65d56..a328a2d 100644
--- a/golim.go
+++ b/golim.go
@@ -89,7 +89,7 @@ func (g *golim) ExecCMD(ctx context.Context) (interface{}, error) {
 	if g.limiterRole != nil {
 		return handleLimiterRoleOperation(g, ctx)
 	}
-	return nil, errors.New("unsupported operation")
+	return nil, errors.New(unsupportedOperationError)
 }
 
 func handleLimiterOperation(g *golim, ctx context.Context) (interface{}, error) {
@@ -99,7 +99,7 @@ func handleLimiterOperation(g *golim, ctx context.Context) (interface{}, error)
 	case removeLimiterOperation:
 		return nil, g.removeRateLimiter(ctx)
 	}
-	return nil, errors.New("unknown limiter operation")
+	return nil, errors.New(unknownLimiterError)
 }
 
 func handleLimiterRoleOperation(g *golim, ctx context.Context) (interface{}, error) {
@@ -111,7 +111,7 @@ func handleLimiterRoleOperation(g *golim, ctx context.Context) (interface{}, err
 	case getRolesOperationID:
 		return g.getRoles(ctx)
 	}
-	return nil, errors.New("unknown limiter role operation")
+	return nil, errors.New(unknownLimiterRoleError)
 }
 
 func newLimiter(db *sql.DB, cache *cache) *golim {
@@ -174,7 +174,7 @@ func (g *golim) createInitCMD() *ff.Command {
 					operation:   createLimiterOperation,
 				}
 			} else {
-				return errors.New("name and destination is required")
+				return errors.New(requiredNameDestinationError)
 			}
 			g.skip = true
 			return nil
@@ -283,7 +283,7 @@ func (g *golim) createGetRolesCMD() *ff.Command {
 					limiterID: *limiterID,
 				}
 			} else {
-				return errors.New("limiter id is required")
+				return errors.New(requiredLimiterIDError)
 			}
 			g.skip = true
 			return nil
diff --git a/proxy.go b/proxy.go
index c5b99c1..8a7ce68 100644
--- a/proxy.go
+++ b/proxy.go
@@ -21,7 +21,7 @@ func runProxy(g *golim) func(w http.ResponseWriter, r *http.Request) {
 			endPoint:  path,
 		}
 		if !isOkRequest(r, g) {
-			http.Error(w, "slow down", http.StatusTooManyRequests)
+			http.Error(w, slowDownError, http.StatusTooManyRequests)
 			return
 		}
 
@@ -39,7 +39,7 @@ func runProxy(g *golim) func(w http.ResponseWriter, r *http.Request) {
 		targetURL := newURL
 		proxyReq, err := http.NewRequest(r.Method, targetURL.String(), r.Body)
 		if err != nil {
-			http.Error(w, "Error creating proxy request", http.StatusInternalServerError)
+			http.Error(w, createProxyError, http.StatusInternalServerError)
 			return
 		}
 		for name, values := range r.Header {
@@ -50,7 +50,7 @@ func runProxy(g *golim) func(w http.ResponseWriter, r *http.Request) {
 
 		resp, err := customTransport.RoundTrip(proxyReq)
 		if err != nil {
-			http.Error(w, "Error sending proxy request", http.StatusInternalServerError)
+			http.Error(w, sendingProxyError, http.StatusInternalServerError)
 			return
 		}
 		defer resp.Body.Close()