diff --git a/components/heap/heap_caps.c b/components/heap/heap_caps.c
index d19f5bd76e..0b27b0b523 100644
--- a/components/heap/heap_caps.c
+++ b/components/heap/heap_caps.c
@@ -171,22 +171,27 @@ HEAP_IRAM_ATTR void *heap_caps_realloc_default( void *ptr, size_t size )
  */
 HEAP_IRAM_ATTR void *heap_caps_malloc_prefer( size_t size, size_t num, ... )
 {
-    va_list argp;
-    va_start( argp, num );
     void *r = NULL;
     uint32_t caps = MALLOC_CAP_DEFAULT;
-    while (num--) {
-        caps = va_arg( argp, uint32_t );
-        r = heap_caps_malloc_base( size, caps );
-        if (r != NULL || size == 0) {
-            break;
+
+    if (num > 0) {
+        va_list argp = {0};
+        va_start(argp, num);
+
+        for ( ; num > 0; --num) {
+            caps = va_arg(argp, uint32_t);
+            r = heap_caps_malloc_base(size, caps);
+            if (r != NULL || size == 0) {
+                break;
+            }
         }
+
+        va_end( argp );
     }
 
-    if (r == NULL && size > 0){
+    if (r == NULL && size > 0) {
         heap_caps_alloc_failed(size, caps, __func__);
     }
-    va_end( argp );
     return r;
 }
 
@@ -195,46 +200,58 @@ HEAP_IRAM_ATTR void *heap_caps_malloc_prefer( size_t size, size_t num, ... )
  */
 HEAP_IRAM_ATTR void *heap_caps_realloc_prefer( void *ptr, size_t size, size_t num, ... )
 {
-    va_list argp;
-    va_start( argp, num );
     void *r = NULL;
     uint32_t caps = MALLOC_CAP_DEFAULT;
-    while (num--) {
-        caps = va_arg( argp, uint32_t );
-        r = heap_caps_realloc_base( ptr, size, caps );
-        if (r != NULL || size == 0) {
-            break;
+
+    if (num > 0) {
+        va_list argp = {0};
+        va_start(argp, num);
+
+        for ( ; num > 0; --num) {
+            caps = va_arg(argp, uint32_t);
+            r = heap_caps_realloc_base(ptr, size, caps);
+            if (r != NULL || size == 0) {
+                break;
+            }
         }
+
+        va_end( argp );
     }
 
-    if (r == NULL && size > 0){
+    if (r == NULL && size > 0) {
         heap_caps_alloc_failed(size, caps, __func__);
     }
-    va_end( argp );
     return r;
 }
 
+
 /*
  Memory callocation as preference in decreasing order.
  */
-HEAP_IRAM_ATTR void *heap_caps_calloc_prefer( size_t n, size_t size, size_t num, ... )
+HEAP_IRAM_ATTR void *heap_caps_calloc_prefer(size_t n, size_t size, size_t num, ...)
 {
-    va_list argp;
-    va_start( argp, num );
     void *r = NULL;
     uint32_t caps = MALLOC_CAP_DEFAULT;
-    while (num--) {
-        caps = va_arg( argp, uint32_t );
-        r = heap_caps_calloc_base( n, size, caps );
-        if (r != NULL || size == 0){
-            break;
+
+    if (num > 0) {
+        va_list argp = {0};
+        va_start(argp, num);
+
+        for (; num > 0; --num) {
+            caps = va_arg(argp, uint32_t);
+            r = heap_caps_calloc_base(n, size, caps);
+            if (r != NULL || size == 0) {
+                break;
+            }
         }
+
+        va_end(argp);
     }
 
-    if (r == NULL && size > 0){
+    if (r == NULL && size > 0) {
         heap_caps_alloc_failed(size, caps, __func__);
     }
-    va_end( argp );
+
     return r;
 }