diff --git a/libc/malloc_debug/malloc_debug.cpp b/libc/malloc_debug/malloc_debug.cpp
index 2e6afff..f662957 100644
--- a/libc/malloc_debug/malloc_debug.cpp
+++ b/libc/malloc_debug/malloc_debug.cpp
@@ -729,7 +729,7 @@
   if (DebugCallsDisabled()) {
     return g_dispatch->aligned_alloc(alignment, size);
   }
-  if (!powerof2(alignment)) {
+  if (!powerof2(alignment) || (size % alignment) != 0) {
     errno = EINVAL;
     return nullptr;
   }
diff --git a/libc/malloc_debug/tests/malloc_debug_unit_tests.cpp b/libc/malloc_debug/tests/malloc_debug_unit_tests.cpp
index 6da95ca..a72db3b 100644
--- a/libc/malloc_debug/tests/malloc_debug_unit_tests.cpp
+++ b/libc/malloc_debug/tests/malloc_debug_unit_tests.cpp
@@ -318,7 +318,7 @@
   ASSERT_LE(1039U, debug_malloc_usable_size(pointer));
   debug_free(pointer);
 
-  pointer = debug_aligned_alloc(128, 15);
+  pointer = debug_aligned_alloc(16, 16);
   ASSERT_TRUE(pointer != nullptr);
   ASSERT_LE(1039U, debug_malloc_usable_size(pointer));
   debug_free(pointer);
@@ -2144,9 +2144,9 @@
   debug_free(pointer);
   expected += android::base::StringPrintf("%d: free %p\n", getpid(), pointer);
 
-  pointer = debug_aligned_alloc(32, 50);
+  pointer = debug_aligned_alloc(32, 64);
   ASSERT_TRUE(pointer != nullptr);
-  expected += android::base::StringPrintf("%d: memalign %p 32 50\n", getpid(), pointer);
+  expected += android::base::StringPrintf("%d: memalign %p 32 64\n", getpid(), pointer);
   debug_free(pointer);
   expected += android::base::StringPrintf("%d: free %p\n", getpid(), pointer);