diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index fb3d86c..40dd383 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -484,3 +484,37 @@ jobs:
         run: |
           cmake --build build --config Release --target qjs
           ls -lh build
+
+  mimalloc-linux:
+    runs-on: ubuntu-24.04
+    env:
+      BUILD_CLI_WITH_MIMALLOC: ON
+      MIMALLOC_SHOW_STATS: 1
+    steps:
+      - uses: actions/checkout@v4
+      - name: install dependencies
+        run: |
+          sudo apt update && sudo apt -y install libmimalloc-dev
+      - name: build
+        run: |
+          make
+      - name: test
+        run: |
+          make test
+
+  mimalloc-macos:
+    runs-on: macos-latest
+    env:
+      BUILD_CLI_WITH_STATIC_MIMALLOC: ON
+      MIMALLOC_SHOW_STATS: 1
+    steps:
+      - uses: actions/checkout@v4
+      - name: install dependencies
+        run: |
+          brew install mimalloc
+      - name: build
+        run: |
+          make
+      - name: test
+        run: |
+          make test
diff --git a/CMakeLists.txt b/CMakeLists.txt
index dd98a58..1f6d377 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -112,6 +112,7 @@ endif()
 xoption(BUILD_EXAMPLES "Build examples" OFF)
 xoption(BUILD_STATIC_QJS_EXE "Build a static qjs executable" OFF)
 xoption(BUILD_CLI_WITH_MIMALLOC "Build the qjs executable with mimalloc" OFF)
+xoption(BUILD_CLI_WITH_STATIC_MIMALLOC "Build the qjs executable with mimalloc (statically linked)" OFF)
 xoption(CONFIG_ASAN "Enable AddressSanitizer (ASan)" OFF)
 xoption(CONFIG_MSAN "Enable MemorySanitizer (MSan)" OFF)
 xoption(CONFIG_UBSAN "Enable UndefinedBehaviorSanitizer (UBSan)" OFF)
@@ -255,10 +256,14 @@ endif()
 if(NOT WIN32)
     set_target_properties(qjs_exe PROPERTIES ENABLE_EXPORTS TRUE)
 endif()
-if(BUILD_CLI_WITH_MIMALLOC)
+if(BUILD_CLI_WITH_MIMALLOC OR BUILD_CLI_WITH_STATIC_MIMALLOC)
     find_package(mimalloc REQUIRED)
-    target_compile_definitions(qjs_exe PRIVATE QJS_USE_MIMALLOC)
-    target_link_libraries(qjs_exe mimalloc-static)
+    # Upstream mimalloc doesn't provide a way to know if both libraries are supported.
+    if(BUILD_CLI_WITH_STATIC_MIMALLOC)
+        target_link_libraries(qjs_exe mimalloc-static)
+    else()
+        target_link_libraries(qjs_exe mimalloc)
+    endif()
 endif()
 
 # Test262 runner
diff --git a/quickjs.c b/quickjs.c
index 5708678..872d7d4 100644
--- a/quickjs.c
+++ b/quickjs.c
@@ -1409,7 +1409,7 @@ void *js_calloc_rt(JSRuntime *rt, size_t count, size_t size)
         return NULL;
 
     s->malloc_count++;
-    s->malloc_size += js__malloc_usable_size(ptr) + MALLOC_OVERHEAD;
+    s->malloc_size += rt->mf.js_malloc_usable_size(ptr) + MALLOC_OVERHEAD;
     return ptr;
 }
 
@@ -1431,7 +1431,7 @@ void *js_malloc_rt(JSRuntime *rt, size_t size)
         return NULL;
 
     s->malloc_count++;
-    s->malloc_size += js__malloc_usable_size(ptr) + MALLOC_OVERHEAD;
+    s->malloc_size += rt->mf.js_malloc_usable_size(ptr) + MALLOC_OVERHEAD;
     return ptr;
 }
 
@@ -1444,7 +1444,7 @@ void js_free_rt(JSRuntime *rt, void *ptr)
 
     s = &rt->malloc_state;
     s->malloc_count--;
-    s->malloc_size -= js__malloc_usable_size(ptr) + MALLOC_OVERHEAD;
+    s->malloc_size -= rt->mf.js_malloc_usable_size(ptr) + MALLOC_OVERHEAD;
     rt->mf.js_free(s->opaque, ptr);
 }
 
@@ -1462,7 +1462,7 @@ void *js_realloc_rt(JSRuntime *rt, void *ptr, size_t size)
         js_free_rt(rt, ptr);
         return NULL;
     }
-    old_size = js__malloc_usable_size(ptr);
+    old_size = rt->mf.js_malloc_usable_size(ptr);
     s = &rt->malloc_state;
     /* When malloc_limit is 0 (unlimited), malloc_limit - 1 will be SIZE_MAX. */
     if (s->malloc_size + size - old_size > s->malloc_limit - 1)
@@ -1472,7 +1472,7 @@ void *js_realloc_rt(JSRuntime *rt, void *ptr, size_t size)
     if (!ptr)
         return NULL;
 
-    s->malloc_size += js__malloc_usable_size(ptr) - old_size;
+    s->malloc_size += rt->mf.js_malloc_usable_size(ptr) - old_size;
     return ptr;
 }
 
@@ -1734,7 +1734,7 @@ JSRuntime *JS_NewRuntime2(const JSMallocFunctions *mf, void *opaque)
         return NULL;
     /* Inline what js_malloc_rt does since we cannot use it here. */
     ms.malloc_count++;
-    ms.malloc_size += js__malloc_usable_size(rt) + MALLOC_OVERHEAD;
+    ms.malloc_size += mf->js_malloc_usable_size(rt) + MALLOC_OVERHEAD;
     rt->mf = *mf;
     if (!rt->mf.js_malloc_usable_size) {
         /* use dummy function if none provided */