diff --git a/lib/system/alloc.nim b/lib/system/alloc.nim
index e6c015dbee..a23702dc1f 100644
--- a/lib/system/alloc.nim
+++ b/lib/system/alloc.nim
@@ -851,12 +851,12 @@ when defined(heaptrack):
 
 proc bigChunkAlignOffset(alignment: int): int {.inline.} =
   ## Compute the alignment offset for big chunk data.
-  if alignment <= MemAlign:
+  if alignment == 0:
     result = 0
   else:
     result = align(sizeof(BigChunk) + sizeof(Cell), alignment) - sizeof(BigChunk) - sizeof(Cell)
 
-proc rawAlloc(a: var MemRegion, requestedSize: int, alignment: int = MemAlign): pointer =
+proc rawAlloc(a: var MemRegion, requestedSize: int, alignment: int = 0): pointer =
   when defined(nimTypeNames):
     inc(a.allocCounter)
   sysAssert(allocInv(a), "rawAlloc: begin")
@@ -868,7 +868,7 @@ proc rawAlloc(a: var MemRegion, requestedSize: int, alignment: int = MemAlign):
 
   # For custom alignments > MemAlign, force big chunk allocation
   # Small chunks cannot handle arbitrary alignments due to fixed cell boundaries
-  if size <= SmallChunkSize-smallChunkOverhead() and alignment <= MemAlign:
+  if size <= SmallChunkSize-smallChunkOverhead() and alignment == 0:
     template fetchSharedCells(tc: PSmallChunk) =
       # Consumes cells from (potentially) foreign threads from `a.sharedFreeLists[s]`
       when defined(gcDestructors):
@@ -1364,4 +1364,4 @@ template instantiateForRegion(allocator: untyped) {.dirty.} =
         #sharedMemStatsShared(sharedHeap.currMem - sharedHeap.freeMem)
   {.pop.}
 
-{.pop.}
+{.pop.}
\ No newline at end of file
diff --git a/lib/system/gc.nim b/lib/system/gc.nim
index 4b02b2f257..bc199b8351 100644
--- a/lib/system/gc.nim
+++ b/lib/system/gc.nim
@@ -459,11 +459,15 @@ proc rawNewObj(typ: PNimType, size: int, gch: var GcHeap): pointer =
   gcAssert(typ.kind in {tyRef, tyString, tySequence}, "newObj: 1")
   collectCT(gch)
   # Use alignment from typ.base if available, otherwise use MemAlign
-  let alignment = if typ.kind == tyRef and typ.base != nil: max(typ.base.align, MemAlign) else: MemAlign
+  let alignment = if typ.kind == tyRef and typ.base != nil and
+        typ.base.align >= MemAlign: typ.base.align else: 0
   var res = cast[PCell](rawAlloc(gch.region, size + sizeof(Cell), alignment))
   #gcAssert typ.kind in {tyString, tySequence} or size >= typ.base.size, "size too small"
   # Check that the user data (after the Cell header) is properly aligned
-  gcAssert((cast[int](cellToUsr(res)) and (alignment-1)) == 0, "newObj: 2")
+  if alignment == 0:
+    gcAssert((cast[int](res) and (MemAlign-1)) == 0, "newObj: 2.1")
+  else:
+    gcAssert((cast[int](cellToUsr(res)) and (alignment-1)) == 0, "newObj: 2.2")
   # now it is buffered in the ZCT
   res.typ = typ
   setFrameInfo(res)
@@ -512,11 +516,15 @@ proc newObjRC1(typ: PNimType, size: int): pointer {.compilerRtl, noinline, raise
   sysAssert(allocInv(gch.region), "newObjRC1 after collectCT")
 
   # Use alignment from typ.base if available, otherwise use MemAlign
-  let alignment = if typ.base != nil: max(typ.base.align, MemAlign) else: MemAlign
+  let alignment = if typ.kind == tyRef and typ.base != nil and
+        typ.base.align >= MemAlign: typ.base.align else: 0
   var res = cast[PCell](rawAlloc(gch.region, size + sizeof(Cell), alignment))
   sysAssert(allocInv(gch.region), "newObjRC1 after rawAlloc")
   # Check that the user data (after the Cell header) is properly aligned
-  sysAssert((cast[int](cellToUsr(res)) and (alignment-1)) == 0, "newObj: 2")
+  if alignment == 0:
+    sysAssert((cast[int](res) and (MemAlign-1)) == 0, "newObj: 2.1")
+  else:
+    sysAssert((cast[int](cellToUsr(res)) and (alignment-1)) == 0, "newObj: 2.2")
   # now it is buffered in the ZCT
   res.typ = typ
   setFrameInfo(res)
@@ -922,4 +930,4 @@ when not defined(useNimRtl):
       result.add "[GC] max stack size: " & $gch.stat.maxStackSize & "\n"
 
 {.pop.} # raises: []
-{.pop.} # profiler: off, stackTrace: off
+{.pop.} # profiler: off, stackTrace: off
\ No newline at end of file