diff --git a/CMakeLists.txt b/CMakeLists.txt
index 951b6f6..3f49a9b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -87,6 +87,7 @@ target_compile_options(
         sist2
         PRIVATE
         -fPIC
+        -Werror
 )
 
 if (SIST_DEBUG)
diff --git a/src/sist.h b/src/sist.h
index 21eb897..46253bd 100644
--- a/src/sist.h
+++ b/src/sist.h
@@ -70,6 +70,6 @@
 #include "web/serve.h"
 #include "web/auth_basic.h"
 
-;
+
 
 #endif
diff --git a/src/util.h b/src/util.h
index 3dc5615..77ffcee 100644
--- a/src/util.h
+++ b/src/util.h
@@ -244,8 +244,8 @@ static void text_buffer_terminate_string(text_buffer_t *buf) {
 __always_inline
 static int text_buffer_append_string(text_buffer_t *buf, const char *str, size_t len) {
 
-    char *ptr = str;
-    char *oldPtr = ptr;
+    const char *ptr = str;
+    const char *oldPtr = ptr;
 
     if (str == NULL || UTF8_END_OF_STRING) {
         return 0;