diff --git a/sys/malloc_thread_safe/malloc_wrappers.c b/sys/malloc_thread_safe/malloc_wrappers.c
index cf226cc402..3210b28093 100644
--- a/sys/malloc_thread_safe/malloc_wrappers.c
+++ b/sys/malloc_thread_safe/malloc_wrappers.c
@@ -53,7 +53,7 @@ void __attribute__((used)) __wrap_free(void *ptr)
 {
     if (IS_USED(MODULE_MALLOC_TRACING)) {
         uinttxtptr_t pc = cpu_get_caller_pc();
-        printf("free(%p) @0x%" PRIxTXTPTR ")\n", ptr, pc);
+        printf("free(%p) @ 0x%" PRIxTXTPTR ")\n", ptr, pc);
     }
     assert(!irq_is_in());
     mutex_lock(&_lock);
@@ -73,7 +73,7 @@ void * __attribute__((used)) __wrap_calloc(size_t nmemb, size_t size)
     size_t total_size;
     if (__builtin_mul_overflow(nmemb, size, &total_size)) {
         if (IS_USED(MODULE_MALLOC_TRACING)) {
-            printf("calloc(%u, %u) @0x%" PRIxTXTPTR " overflowed\n",
+            printf("calloc(%u, %u) @ 0x%" PRIxTXTPTR " overflowed\n",
                    (unsigned)nmemb, (unsigned)size, pc);
         }
         return NULL;
@@ -87,7 +87,7 @@ void * __attribute__((used)) __wrap_calloc(size_t nmemb, size_t size)
     }
 
     if (IS_USED(MODULE_MALLOC_TRACING)) {
-        printf("calloc(%u, %u) @0x%" PRIxTXTPTR " returned %p\n",
+        printf("calloc(%u, %u) @ 0x%" PRIxTXTPTR " returned %p\n",
                (unsigned)nmemb, (unsigned)size, pc, res);
     }