diff --git a/include/kernaux/memmap.h b/include/kernaux/memmap.h
index c0537a94..837400f1 100644
--- a/include/kernaux/memmap.h
+++ b/include/kernaux/memmap.h
@@ -29,7 +29,7 @@ typedef struct KernAux_MemMap {
 struct KernAux_MemMap KernAux_MemMap_create(size_t memory_size);
 void KernAux_MemMap_init(KernAux_MemMap memmap, size_t memory_size);
 
-/// @warning Must only be called with unfinished memmap, otherwise panics.
+/// @warning Must only be called with NOT finished memmap, otherwise panics.
 bool KernAux_MemMap_add_entry(
     KernAux_MemMap memmap,
     bool is_available,
@@ -38,7 +38,7 @@ bool KernAux_MemMap_add_entry(
     size_t size
 );
 
-/// @warning Must only be called with unfinished memmap, otherwise panics.
+/// @warning Must only be called with NOT finished memmap, otherwise panics.
 bool KernAux_MemMap_finish(KernAux_MemMap memmap);
 
 /// @warning Must only be called with finished memmap, otherwise panics.
diff --git a/tests/test_memmap.c b/tests/test_memmap.c
index 825d7cd5..2694d0e9 100644
--- a/tests/test_memmap.c
+++ b/tests/test_memmap.c
@@ -2,6 +2,7 @@
 #include "config.h"
 #endif
 
+#include <kernaux/assert.h>
 #include <kernaux/memmap.h>
 
 #include <assert.h>
@@ -11,11 +12,27 @@
 
 static KernAux_MemMap memmap;
 
+static unsigned int assert_count_exp = 0;
+static unsigned int assert_count_ctr = 0;
+
+static const char *assert_last_file = NULL;
+
+static void assert_cb(
+    const char *const file,
+    __attribute__((unused)) const int line,
+    __attribute__((unused)) const char *const msg
+) {
+    ++assert_count_ctr;
+    assert_last_file = file;
+}
+
 #define MEMSET memset(memmap, 0xff, sizeof(memmap))
 #define MEMMAP (*memmap)
 
 int main()
 {
+    kernaux_assert_cb = assert_cb;
+
     {
         MEMSET;
         KernAux_MemMap_init(memmap, 0);
@@ -31,6 +48,12 @@ int main()
         assert(MEMMAP.entries_count == 0);
 
         assert(KernAux_MemMap_entry_by_index(memmap, 0) == NULL);
+
+        assert(assert_count_ctr == assert_count_exp);
+        assert(!KernAux_MemMap_finish(memmap));
+        assert(assert_count_ctr == ++assert_count_exp);
+        assert(strstr(assert_last_file, "src/memmap.c") != NULL);
+        assert_last_file = NULL;
     }
 
     {
@@ -140,7 +163,11 @@ int main()
         assert(MEMMAP.entries[0].end == 1);
         assert(MEMMAP.entries[0].limit == 2);
 
+        assert(assert_count_ctr == assert_count_exp);
         assert(KernAux_MemMap_entry_by_index(memmap, 0) == NULL);
+        assert(assert_count_ctr == ++assert_count_exp);
+        assert(strstr(assert_last_file, "src/memmap.c") != NULL);
+        assert_last_file = NULL;
     }
 
     {
@@ -185,5 +212,7 @@ int main()
         assert(KernAux_MemMap_entry_by_index(memmap, 1) == &MEMMAP.entries[1]);
     }
 
+    assert(assert_count_ctr == assert_count_exp);
+
     return 0;
 }