diff --git a/include/tlibc/errors.h b/include/tlibc/errors.h
index b57e70f..a7909ed 100755
--- a/include/tlibc/errors.h
+++ b/include/tlibc/errors.h
@@ -26,7 +26,7 @@ typedef struct Error {
     List(ErrorCallPos) call_stack;
 } Error;
 
-Error* Error_create(const char* msg, bool is_msg_on_heap, ErrorCallPos p,
+Error* Error_create(str msg, bool is_msg_on_heap, ErrorCallPos p,
     u16 error_code_page, u32 error_code);
 void Error_free(Error* e);
 void Error_addCallPos(Error* e, ErrorCallPos p);
@@ -83,9 +83,11 @@ typedef struct Result_ {
     .u = 0 \
 }
 #define RESULT_ERROR_CODE_FMT(CODE_PAGE, CODE, FORMAT, ARGS...) \
-    RESULT_ERROR_CODE(CODE_PAGE, CODE, sprintf_malloc(FORMAT ,##ARGS), true)
+    RESULT_ERROR_CODE(CODE_PAGE, CODE, str_from_cstr(sprintf_malloc(FORMAT ,##ARGS)), true)
 #define RESULT_ERROR(MSG, IS_MSG_ON_HEAP) \
     RESULT_ERROR_CODE(NONE, 0, MSG, IS_MSG_ON_HEAP);
+#define RESULT_ERROR_LITERAL(MSG) \
+    RESULT_ERROR(STR((MSG)), false)
 #define RESULT_ERROR_FMT(FORMAT, ARGS...) \
     RESULT_ERROR_CODE_FMT(NONE, 0, FORMAT ,##ARGS)
 
@@ -153,4 +155,4 @@ typedef struct Result_ {
     }\
 } while(0)
 
-#define try_assert(EXPR) if(!(EXPR)) { Return RESULT_ERROR(("assertion must be true: " #EXPR), false); } 
+#define try_assert(EXPR) if(!(EXPR)) { Return RESULT_ERROR_LITERAL("assertion must be true: " #EXPR); } 
diff --git a/src/errors.c b/src/errors.c
index 2ecbe22..0f85933 100755
--- a/src/errors.c
+++ b/src/errors.c
@@ -3,11 +3,11 @@
 
 #define ERRMSG_LENGTH 1024
 
-Error* Error_create(const char* msg, bool is_msg_on_heap, ErrorCallPos p,
+Error* Error_create(str msg, bool is_msg_on_heap, ErrorCallPos p,
     u16 error_code_page, u32 error_code)
 {
     Error* e = (Error*)malloc(sizeof(Error));
-    e->msg = str_construct((char*)(void*)msg, strlen(msg), true);
+    e->msg = msg;
     e->is_msg_on_heap = is_msg_on_heap;
     e->error_code_page = error_code_page;
     e->error_code = error_code;