diff --git a/lelib/lecore.h b/lelib/lecore.h
index e2aaee1..f7ecd52 100644
--- a/lelib/lecore.h
+++ b/lelib/lecore.h
@@ -27,6 +27,7 @@ void le_poke(void);
 void le_log(const char* message);
 void le_write_string(NSString* string);
 void le_set_token(const char* token);
+bool is_valid_token(const char* token,size_t *token_length);
 void le_set_debug_logs(bool verbose);
 
 #endif
diff --git a/lelib/lecore.m b/lelib/lecore.m
index ccba9d5..5219e2d 100644
--- a/lelib/lecore.m
+++ b/lelib/lecore.m
@@ -173,7 +173,12 @@ void le_log(const char* message)
 {
     dispatch_sync(le_write_queue, ^{
         
-        size_t token_length = strlen(le_token);
+        size_t token_length;
+        
+        if(!is_valid_token(le_token,&token_length))
+            return ;
+        
+
         size_t max_length = MAXIMUM_LOGENTRY_SIZE - token_length - 2; // minus token length, space separator and lf
         
         size_t length = strlen(message);
@@ -199,27 +204,29 @@ void le_write_string(NSString* string)
 {
     dispatch_sync(le_write_queue, ^{
         
-        NSUInteger tokenLength = strlen(le_token);
+        size_t token_length;
+        if(!is_valid_token(le_token,&token_length))
+            return ;
         
-        NSUInteger maxLength = MAXIMUM_LOGENTRY_SIZE - tokenLength - 2; // minus token length, space separator and \n
+        NSUInteger maxLength = MAXIMUM_LOGENTRY_SIZE - token_length - 2; // minus token length, space separator and \n
         if ([string length] > maxLength) {
             LE_DEBUG(@"Too large message, it will be truncated");
         }
         
-        memcpy(buffer, le_token, tokenLength);
-        buffer[tokenLength] = ' ';
+        memcpy(buffer, le_token, token_length);
+        buffer[token_length] = ' ';
 
         NSRange range = {.location = 0, .length = [string length]};
         
         NSUInteger usedLength = 0;
-        BOOL r = [string getBytes:(buffer + tokenLength + 1) maxLength:maxLength usedLength:&usedLength encoding:NSUTF8StringEncoding options:NSStringEncodingConversionAllowLossy range:range remainingRange:NULL];
+        BOOL r = [string getBytes:(buffer + token_length + 1) maxLength:maxLength usedLength:&usedLength encoding:NSUTF8StringEncoding options:NSStringEncodingConversionAllowLossy range:range remainingRange:NULL];
         
         if (!r) {
             LE_DEBUG(@"Error converting message characters.");
             return;
         }
         
-        NSUInteger totalLength = tokenLength + 1 + usedLength;
+        NSUInteger totalLength = token_length + 1 + usedLength;
         buffer[totalLength++] = '\n';
         write_buffer((size_t)totalLength);
     });
@@ -227,24 +234,15 @@ void le_write_string(NSString* string)
 
 void le_set_token(const char* token)
 {
-    size_t length = strlen(token);
-    
-    if (length < TOKEN_LENGTH) {
-        LE_DEBUG(@"Invalid token length, it will not be used.");
-        return;
-    }
-    
-    if (length >= MAXIMUM_LOGENTRY_SIZE) {
-        LE_DEBUG(@"Token too large, it will not be used.");
+    size_t length ;
+    if(!is_valid_token(token,&length))
         return;
-    }
     
     char* local_buffer = malloc(length + 1);
     if (!local_buffer) {
         LE_DEBUG(@"Can't allocate token buffer.");
-        return;
+        return ;
     }
-    
     strlcpy(local_buffer, token, length + 1);
     
     dispatch_sync(le_write_queue, ^{
@@ -252,6 +250,29 @@ void le_set_token(const char* token)
     });
 }
 
+bool is_valid_token(const char * token,size_t* token_length)
+{
+    size_t length = 0;
+    
+    if (token == NULL) {
+        NSLog(@"nil token\n");
+        LE_DEBUG(@"nil token");
+        return false;
+    }
+    
+    length = strlen(token);
+    
+    if(token_length != NULL)
+        *token_length = length;
+    
+    if (length < TOKEN_LENGTH) {
+        LE_DEBUG(@"Invalid token length, it will not be used.");
+        return false;
+    }
+    
+    return true;
+}
+
 void le_set_debug_logs(bool debug) {
     le_debug_logs = debug;
 }
diff --git a/lelibTests/lelibTests.m b/lelibTests/lelibTests.m
index eae007d..80aa215 100644
--- a/lelibTests/lelibTests.m
+++ b/lelibTests/lelibTests.m
@@ -39,5 +39,12 @@ - (void)testLog
     
     XCTFail(@"Test exited runloop");
 }
+- (void)testNilToken{
+    
+    LELog* log = [LELog sharedInstance];
+    log.token = nil;
+    [log log:@"try to log without token"];
+
+}
 
 @end