diff --git a/src/log.c b/src/log.c
index 04e90eb20f0..f65e8d1006d 100644
--- a/src/log.c
+++ b/src/log.c
@@ -618,18 +618,13 @@ int log_meta(
         return r;
 }
 
-void log_assert(
-        const char*file,
-        int line,
-        const char *func,
-        const char *format, ...) {
-
+_noreturn_ static void log_assert(const char *text, const char *file, int line, const char *func, const char *format) {
         static char buffer[LINE_MAX];
-        va_list ap;
 
-        va_start(ap, format);
-        vsnprintf(buffer, sizeof(buffer), format, ap);
-        va_end(ap);
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wformat-nonliteral"
+        snprintf(buffer, sizeof(buffer), format, text, file, line, func);
+#pragma GCC diagnostic pop
 
         char_array_0(buffer);
         log_abort_msg = buffer;
@@ -638,6 +633,14 @@ void log_assert(
         abort();
 }
 
+void log_assert_failed(const char *text, const char *file, int line, const char *func) {
+        log_assert(text, file, line, func, "Assertion '%s' failed at %s:%u, function %s(). Aborting.");
+}
+
+void log_assert_failed_unreachable(const char *text, const char *file, int line, const char *func) {
+        log_assert(text, file, line, func, "Code should not be reached '%s' at %s:%u, function %s(). Aborting.");
+}
+
 int log_set_target_from_string(const char *e) {
         LogTarget t;
 
diff --git a/src/log.h b/src/log.h
index 6ab07a54222..7028a13275f 100644
--- a/src/log.h
+++ b/src/log.h
@@ -73,11 +73,8 @@ int log_meta(
         const char *func,
         const char *format, ...) _printf_attr_(5,6);
 
-_noreturn_ void log_assert(
-        const char*file,
-        int line,
-        const char *func,
-        const char *format, ...) _printf_attr_(4,5);
+_noreturn_ void log_assert_failed(const char *text, const char *file, int line, const char *func);
+_noreturn_ void log_assert_failed_unreachable(const char *text, const char *file, int line, const char *func);
 
 /* This modifies the buffer passed! */
 int log_dump_internal(
diff --git a/src/macro.h b/src/macro.h
index 3f30aa78920..58de001f262 100644
--- a/src/macro.h
+++ b/src/macro.h
@@ -91,9 +91,7 @@ static inline size_t ALIGN_TO(size_t l, size_t ali) {
 #define assert_se(expr)                                                 \
         do {                                                            \
                 if (_unlikely_(!(expr)))                                \
-                        log_assert(__FILE__, __LINE__, __PRETTY_FUNCTION__, \
-                                   "Assertion '%s' failed at %s:%u, function %s(). Aborting.", \
-                                   #expr , __FILE__, __LINE__, __PRETTY_FUNCTION__); \
+                        log_assert_failed(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
         } while (false)                                                 \
 
 /* We override the glibc assert() here. */
@@ -106,9 +104,7 @@ static inline size_t ALIGN_TO(size_t l, size_t ali) {
 
 #define assert_not_reached(t)                                           \
         do {                                                            \
-                log_assert(__FILE__, __LINE__, __PRETTY_FUNCTION__,     \
-                           "Code should not be reached '%s' at %s:%u, function %s(). Aborting.", \
-                           t, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
+                log_assert_failed_unreachable(t, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
         } while (false)
 
 #define assert_cc(expr)                            \