diff --git a/lib/system/mmdisp.nim b/lib/system/mmdisp.nim
index 96dc86bfd2..3317ba6270 100644
--- a/lib/system/mmdisp.nim
+++ b/lib/system/mmdisp.nim
@@ -57,6 +57,16 @@ elif defined(gogc):
 elif (defined(nogc) or defined(gcDestructors)) and defined(useMalloc):
   include system / mm / malloc
 
+  when defined(nogc):
+    proc GC_getStatistics(): string = ""
+    proc newObj(typ: PNimType, size: int): pointer {.compilerproc.} =
+      result = alloc0(size)
+
+    proc newSeq(typ: PNimType, len: int): pointer {.compilerproc.} =
+      result = newObj(typ, align(GenericSeqSize, typ.align) + len * typ.base.size)
+      cast[PGenericSeq](result).len = len
+      cast[PGenericSeq](result).reserved = len
+
 elif defined(nogc):
   include system / mm / none
 
diff --git a/tests/system/tgcnone.nim b/tests/system/tgcnone.nim
new file mode 100644
index 0000000000..700176d5f8
--- /dev/null
+++ b/tests/system/tgcnone.nim
@@ -0,0 +1,6 @@
+discard """
+  matrix: "--gc:none -d:useMalloc"
+"""
+# bug #15617
+let x = 4
+doAssert x == 4