diff --git a/src/error.c b/src/error.c
index 0bdafc2..06129c7 100644
--- a/src/error.c
+++ b/src/error.c
@@ -16,7 +16,7 @@
     (void)vsnprintf(buf, PRINT_BUFFER_SIZE, fmt, args); \
     va_end(args);
 
-void debug(char const* fmt, ...) {
+void debug(char const* restrict fmt, ...) {
     char const* env = getenv("DEBUG");
     if (env == NULL || *env != '1')
         return;
@@ -27,25 +27,25 @@ void debug(char const* fmt, ...) {
     (void)fprintf(stdout, "\033[95m%s\033[0m\n", buf);
 }
 
-void info(char const* fmt, ...) {
+void info(char const* restrict fmt, ...) {
     char buf[PRINT_BUFFER_SIZE] = {0};
     write_args(buf, fmt);
     (void)fprintf(stdout, "\033[0m%s\033[0m\n", buf); // write colour here for consistency
 }
 
-void warn(char const* fmt, ...) {
+void warn(char const* restrict fmt, ...) {
     char buf[PRINT_BUFFER_SIZE] = {0};
     write_args(buf, fmt);
     (void)fprintf(stderr, "\033[93mW: %s\033[0m\n", buf);
 }
 
-void error(char const* fmt, ...) {
+void error(char const* restrict fmt, ...) {
     char buf[PRINT_BUFFER_SIZE] = {0};
     write_args(buf, fmt);
-    (void)fprintf(stderr, "\033[91mE: %s\033[0m", buf);
+    (void)fprintf(stderr, "\033[91mE: %s\033[0m\n", buf);
 }
 
-noreturn void fatal(gamestatus error_code, char const* fname, uint32_t ln, char const* fmt, ...) {
+noreturn void fatal(unsigned error_code, char const* restrict fname, unsigned ln, char const* restrict fmt, ...) {
     char buf1[PRINT_BUFFER_SIZE] = {0};
     write_args(buf1, fmt);
 
diff --git a/src/error.h b/src/error.h
index 8f7c3c0..469c61b 100644
--- a/src/error.h
+++ b/src/error.h
@@ -28,12 +28,11 @@ enum gamestatus {
     STATUS_RUNNING = -1,
     // clang-format on
 };
-typedef int8_t gamestatus;
 
-__attribute__((format(printf, 1, 2))) void debug(char const*, ...); // prints a debug message to stdout if the DEBUG environment variable is set, otherwise the call is ignored.
-__attribute__((format(printf, 1, 2))) void info(char const*, ...);  // prints an info message to stdout
-__attribute__((format(printf, 1, 2))) void warn(char const*, ...);  // prints a warning message to stderr
-__attribute__((format(printf, 1, 2))) void error(char const*, ...); // prints an warning message to stderr
+__attribute__((nonnull(1))) __attribute__((format(printf, 1, 2))) void debug(char const* restrict, ...); // prints a debug message to stdout if the DEBUG environment variable is set, otherwise the call is ignored.
+__attribute__((nonnull(1))) __attribute__((format(printf, 1, 2))) void info(char const* restrict, ...);  // prints an info message to stdout
+__attribute__((nonnull(1))) __attribute__((format(printf, 1, 2))) void warn(char const* restrict, ...);  // prints a warning message to stderr
+__attribute__((nonnull(1))) __attribute__((format(printf, 1, 2))) void error(char const* restrcit, ...); // prints an warning message to stderr
 
 // prints an error message to stderr before exiting
-__attribute__((format(printf, 4, 5))) noreturn void fatal(gamestatus, char const* file_name, uint32_t line, char const* fmt, ...);
+__attribute__((nonnull(2, 5))) __attribute__((format(printf, 4, 5))) noreturn void fatal(unsigned, char const* restrict file_name, unsigned line, char const* restrict fmt, ...);