diff --git a/lib/std/assertions.nim b/lib/std/assertions.nim
index f31a8465afb97..771e7473b0818 100644
--- a/lib/std/assertions.nim
+++ b/lib/std/assertions.nim
@@ -9,7 +9,8 @@
 
 when not defined(nimPreviewSlimSystem) and not declared(sysFatal):
   include "system/rawquits"
-  include "system/fatal"
+  when hostOS != "standalone":
+    include "system/fatal"
 
 ## This module implements assertion handling.
 
@@ -37,7 +38,10 @@ proc raiseAssert*(msg: string) {.noinline, noreturn, nosinks.} =
   when defined(nimPreviewSlimSystem):
     raise newException(AssertionDefect, msg)
   else:
-    sysFatal(AssertionDefect, msg)
+    when declared(sysFatal):
+      sysFatal(AssertionDefect, msg)
+    else:
+      raise newException(AssertionDefect, msg)
 
 proc failedAssertImpl*(msg: string) {.raises: [], tags: [].} =
   ## Raises an `AssertionDefect` with `msg`, but this is hidden
diff --git a/lib/system.nim b/lib/system.nim
index 9ef8128c2d468..8a0abdd20dddd 100644
--- a/lib/system.nim
+++ b/lib/system.nim
@@ -32,6 +32,7 @@ func zeroDefault*[T](_: typedesc[T]): T {.magic: "ZeroDefault".} =
   ## * `default <#default,typedesc[T]>`_
 
 include "system/compilation"
+include "system/fatal_shared"
 
 {.push warning[GcMem]: off, warning[Uninit]: off.}
 # {.push hints: off.}
@@ -1139,6 +1140,10 @@ include system/rawquits
 when defined(genode):
   export GenodeEnv
 
+when not declared(sysFatal) and hostOS != "standalone":
+  include "system/fatal"
+
+
 template sysAssert(cond: bool, msg: string) =
   when defined(useSysAssert):
     if not cond:
@@ -2570,6 +2575,11 @@ type
   NimNode* {.magic: "PNimrodNode".} = ref NimNodeObj
     ## Represents a Nim AST node. Macros operate on this type.
 
+when not declared(sysFatal):
+  include "system/fatal"
+  when hostOS == "standalone" and declared(includePanicoverrideIfReady):
+    includePanicoverrideIfReady()
+
 type
   ForLoopStmt* {.compilerproc.} = object ## \
     ## A special type that marks a macro as a `for-loop macro`:idx:.
diff --git a/lib/system/assign.nim b/lib/system/assign.nim
index 9f4cbc0feb2df..009a4a1bcff4a 100644
--- a/lib/system/assign.nim
+++ b/lib/system/assign.nim
@@ -9,6 +9,19 @@
 
 include seqs_v2_reimpl
 
+when not declared(sysFatal):
+  template sysFatalOrRaise(exceptn: typedesc[Defect], message: string, arg: string = ""): untyped =
+    if arg == "":
+      raise newException(exceptn, message)
+    else:
+      raise newException(exceptn, message & arg)
+else:
+  template sysFatalOrRaise(exceptn: typedesc[Defect], message: string, arg: string = ""): untyped =
+    if arg == "":
+      sysFatal(exceptn, message)
+    else:
+      sysFatal(exceptn, message, arg)
+
 proc genericResetAux(dest: pointer, n: ptr TNimNode) {.benign.}
 
 proc genericAssignAux(dest, src: pointer, mt: PNimType, shallow: bool) {.benign.}
@@ -289,10 +302,10 @@ proc FieldDiscriminantCheck(oldDiscVal, newDiscVal: int,
   let newBranch = selectBranch(newDiscVal, L, a)
   when defined(nimOldCaseObjects):
     if newBranch != oldBranch and oldDiscVal != 0:
-      sysFatal(FieldDefect, "assignment to discriminant changes object branch")
+      sysFatalOrRaise(FieldDefect, "assignment to discriminant changes object branch")
   else:
     if newBranch != oldBranch:
       if oldDiscVal != 0:
-        sysFatal(FieldDefect, "assignment to discriminant changes object branch")
+        sysFatalOrRaise(FieldDefect, "assignment to discriminant changes object branch")
       else:
-        sysFatal(FieldDefect, "assignment to discriminant changes object branch; compile with -d:nimOldCaseObjects for a transition period")
+        sysFatalOrRaise(FieldDefect, "assignment to discriminant changes object branch; compile with -d:nimOldCaseObjects for a transition period")
diff --git a/lib/system/chcks.nim b/lib/system/chcks.nim
index 1a7d7f0a90388..27009188858d7 100644
--- a/lib/system/chcks.nim
+++ b/lib/system/chcks.nim
@@ -12,62 +12,75 @@ include system/indexerrors
 when defined(nimPreviewSlimSystem):
   import std/formatfloat
 
+when not declared(sysFatal):
+  template sysFatalOrRaise(exceptn: typedesc[Defect], message: string, arg: string = ""): untyped =
+    if arg == "":
+      raise newException(exceptn, message)
+    else:
+      raise newException(exceptn, message & arg)
+else:
+  template sysFatalOrRaise(exceptn: typedesc[Defect], message: string, arg: string = ""): untyped =
+    if arg == "":
+      sysFatal(exceptn, message)
+    else:
+      sysFatal(exceptn, message, arg)
+
 proc raiseRangeError(val: BiggestInt) {.compilerproc, noinline.} =
   when hostOS == "standalone":
-    sysFatal(RangeDefect, "value out of range")
+    sysFatalOrRaise(RangeDefect, "value out of range")
   else:
-    sysFatal(RangeDefect, "value out of range: ", $val)
+    sysFatalOrRaise(RangeDefect, "value out of range: ", $val)
 
 proc raiseIndexError4(l1, h1, h2: int) {.compilerproc, noinline.} =
-  sysFatal(IndexDefect, "index out of bounds: " & $l1 & ".." & $h1 & " notin 0.." & $(h2 - 1))
+  sysFatalOrRaise(IndexDefect, "index out of bounds: " & $l1 & ".." & $h1 & " notin 0.." & $(h2 - 1))
 
 proc raiseIndexError3(i, a, b: int) {.compilerproc, noinline.} =
-  sysFatal(IndexDefect, formatErrorIndexBound(i, a, b))
+  sysFatalOrRaise(IndexDefect, formatErrorIndexBound(i, a, b))
 
 proc raiseIndexError2(i, n: int) {.compilerproc, noinline.} =
-  sysFatal(IndexDefect, formatErrorIndexBound(i, n))
+  sysFatalOrRaise(IndexDefect, formatErrorIndexBound(i, n))
 
 proc raiseIndexError() {.compilerproc, noinline.} =
-  sysFatal(IndexDefect, "index out of bounds")
+  sysFatalOrRaise(IndexDefect, "index out of bounds")
 
 proc raiseFieldError(f: string) {.compilerproc, noinline.} =
   ## remove after bootstrap > 1.5.1
-  sysFatal(FieldDefect, f)
+  sysFatalOrRaise(FieldDefect, f)
 
 when defined(nimV2):
   proc raiseFieldError2(f: string, discVal: int) {.compilerproc, noinline.} =
     ## raised when field is inaccessible given runtime value of discriminant
-    sysFatal(FieldDefect, f & $discVal & "'")
+    sysFatalOrRaise(FieldDefect, f & $discVal & "'")
 
   proc raiseFieldErrorStr(f: string, discVal: string) {.compilerproc, noinline.} =
     ## raised when field is inaccessible given runtime value of discriminant
-    sysFatal(FieldDefect, formatFieldDefect(f, discVal))
+    sysFatalOrRaise(FieldDefect, formatFieldDefect(f, discVal))
 else:
   proc raiseFieldError2(f: string, discVal: string) {.compilerproc, noinline.} =
     ## raised when field is inaccessible given runtime value of discriminant
-    sysFatal(FieldDefect, formatFieldDefect(f, discVal))
+    sysFatalOrRaise(FieldDefect, formatFieldDefect(f, discVal))
 
 proc raiseRangeErrorI(i, a, b: BiggestInt) {.compilerproc, noinline.} =
   when defined(standalone):
-    sysFatal(RangeDefect, "value out of range")
+    sysFatalOrRaise(RangeDefect, "value out of range")
   else:
-    sysFatal(RangeDefect, "value out of range: " & $i & " notin " & $a & " .. " & $b)
+    sysFatalOrRaise(RangeDefect, "value out of range: " & $i & " notin " & $a & " .. " & $b)
 
 proc raiseRangeErrorF(i, a, b: float) {.compilerproc, noinline.} =
   when defined(standalone):
-    sysFatal(RangeDefect, "value out of range")
+    sysFatalOrRaise(RangeDefect, "value out of range")
   else:
-    sysFatal(RangeDefect, "value out of range: " & $i & " notin " & $a & " .. " & $b)
+    sysFatalOrRaise(RangeDefect, "value out of range: " & $i & " notin " & $a & " .. " & $b)
 
 proc raiseRangeErrorU(i, a, b: uint64) {.compilerproc, noinline.} =
   # todo: better error reporting
-  sysFatal(RangeDefect, "value out of range")
+  sysFatalOrRaise(RangeDefect, "value out of range")
 
 proc raiseRangeErrorNoArgs() {.compilerproc, noinline.} =
-  sysFatal(RangeDefect, "value out of range")
+  sysFatalOrRaise(RangeDefect, "value out of range")
 
 proc raiseObjectConversionError() {.compilerproc, noinline.} =
-  sysFatal(ObjectConversionDefect, "invalid object conversion")
+  sysFatalOrRaise(ObjectConversionDefect, "invalid object conversion")
 
 proc chckIndx(i, a, b: int): int =
   if i >= a and i <= b:
@@ -95,7 +108,7 @@ proc chckRangeU(i, a, b: uint64): uint64 {.compilerproc.} =
     return i
   else:
     result = 0
-    sysFatal(RangeDefect, "value out of range")
+    sysFatalOrRaise(RangeDefect, "value out of range")
 
 proc chckRangeF(x, a, b: float): float =
   if x >= a and x <= b:
@@ -103,17 +116,17 @@ proc chckRangeF(x, a, b: float): float =
   else:
     result = 0.0
     when hostOS == "standalone":
-      sysFatal(RangeDefect, "value out of range")
+      sysFatalOrRaise(RangeDefect, "value out of range")
     else:
-      sysFatal(RangeDefect, "value out of range: ", $x)
+      sysFatalOrRaise(RangeDefect, "value out of range: ", $x)
 
 proc chckNil(p: pointer) =
   if p == nil:
-    sysFatal(NilAccessDefect, "attempt to write to a nil address")
+    sysFatalOrRaise(NilAccessDefect, "attempt to write to a nil address")
 
 proc chckNilDisp(p: pointer) {.compilerproc.} =
   if p == nil:
-    sysFatal(NilAccessDefect, "cannot dispatch; dispatcher is nil")
+    sysFatalOrRaise(NilAccessDefect, "cannot dispatch; dispatcher is nil")
 
 when not defined(nimV2):
 
@@ -123,12 +136,12 @@ when not defined(nimV2):
     if x == subclass: return # optimized fast path
     while x != subclass:
       if x == nil:
-        sysFatal(ObjectConversionDefect, "invalid object conversion")
+        sysFatalOrRaise(ObjectConversionDefect, "invalid object conversion")
       x = x.base
 
   proc chckObjAsgn(a, b: PNimType) {.compilerproc, inline.} =
     if a != b:
-      sysFatal(ObjectAssignmentDefect, "invalid object assignment")
+      sysFatalOrRaise(ObjectAssignmentDefect, "invalid object assignment")
 
   type ObjCheckCache = array[0..1, PNimType]
 
@@ -163,4 +176,4 @@ when not defined(nimV2):
 
 when defined(nimV2):
   proc raiseObjectCaseTransition() {.compilerproc.} =
-    sysFatal(FieldDefect, "assignment to discriminant changes object branch")
+    sysFatalOrRaise(FieldDefect, "assignment to discriminant changes object branch")
diff --git a/lib/system/embedded.nim b/lib/system/embedded.nim
index 5d1d12accb0af..d0d7d8f44add0 100644
--- a/lib/system/embedded.nim
+++ b/lib/system/embedded.nim
@@ -34,17 +34,29 @@ const
 proc quitOrDebug() {.noreturn, importc: "abort", header: "<stdlib.h>", nodecl.}
 
 proc raiseException(e: ref Exception, ename: cstring) {.compilerRtl.} =
-  sysFatal(ReraiseDefect, "exception handling is not available")
+  when declared(sysFatal):
+    sysFatal(ReraiseDefect, "exception handling is not available")
+  else:
+    raise newException(ReraiseDefect, "exception handling is not available")
 
 proc raiseExceptionEx(e: sink(ref Exception), ename, procname, filename: cstring,
                       line: int) {.compilerRtl.} =
-  sysFatal(ReraiseDefect, "exception handling is not available")
+  when declared(sysFatal):
+    sysFatal(ReraiseDefect, "exception handling is not available")
+  else:
+    raise newException(ReraiseDefect, "exception handling is not available")
 
 proc reraiseException() {.compilerRtl.} =
-  sysFatal(ReraiseDefect, "no exception to reraise")
+  when declared(sysFatal):
+    sysFatal(ReraiseDefect, "no exception to reraise")
+  else:
+    raise newException(ReraiseDefect, "no exception to reraise")
 
 proc raiseDefect() {.compilerRtl.} =
-  sysFatal(ReraiseDefect, "exception handling is not available")
+  when declared(sysFatal):
+    sysFatal(ReraiseDefect, "exception handling is not available")
+  else:
+    raise newException(ReraiseDefect, "exception handling is not available")
 
 proc writeStackTrace() = discard
 
@@ -59,4 +71,7 @@ when gotoBasedExceptions:
 
   proc nimTestErrorFlag() {.compilerRtl.} =
     if nimInErrorMode:
-      sysFatal(ReraiseDefect, "exception handling is not available")
+      when declared(sysFatal):
+        sysFatal(ReraiseDefect, "exception handling is not available")
+      else:
+        raise newException(ReraiseDefect, "exception handling is not available")
diff --git a/lib/system/fatal.nim b/lib/system/fatal.nim
index 25c05e52d9cc8..87308550bf7b5 100644
--- a/lib/system/fatal.nim
+++ b/lib/system/fatal.nim
@@ -9,19 +9,29 @@
 
 {.push profiler: off.}
 
-const
-  gotoBasedExceptions = compileOption("exceptions", "goto")
-  quirkyExceptions = compileOption("exceptions", "quirky")
+include "system/fatal_shared"
 
 when hostOS == "standalone":
-  include "$projectpath/panicoverride"
+  when declared(repr) and declared(NimNode):
+    include "$projectpath/panicoverride"
+  else:
+    template includePanicoverrideIfReady() =
+      when declared(repr) and declared(NimNode):
+        include "$projectpath/panicoverride"
 
   func sysFatal(exceptn: typedesc[Defect], message: string) {.inline.} =
-    panic(message)
+    when declared(panic):
+      panic(message)
+    else:
+      raise newException(exceptn, message)
 
   func sysFatal(exceptn: typedesc[Defect], message, arg: string) {.inline.} =
-    rawoutput(message)
-    panic(arg)
+    when declared(rawoutput):
+      rawoutput(message)
+    when declared(panic):
+      panic(arg)
+    else:
+      raise newException(exceptn, message & arg)
 
 elif quirkyExceptions and not defined(nimscript):
   import ansi_c
diff --git a/lib/system/fatal_shared.nim b/lib/system/fatal_shared.nim
new file mode 100644
index 0000000000000..26467b943978b
--- /dev/null
+++ b/lib/system/fatal_shared.nim
@@ -0,0 +1,5 @@
+when not declared(gotoBasedExceptions):
+  const gotoBasedExceptions* = compileOption("exceptions", "goto")
+
+when not declared(quirkyExceptions):
+  const quirkyExceptions* = compileOption("exceptions", "quirky")
\ No newline at end of file
diff --git a/lib/system/indices.nim b/lib/system/indices.nim
index f2bad2528f770..6c4b40735f3d5 100644
--- a/lib/system/indices.nim
+++ b/lib/system/indices.nim
@@ -130,7 +130,10 @@ proc `[]=`*[Idx, T; U, V: Ordinal](a: var array[Idx, T], x: HSlice[U, V], b: ope
   if L == b.len:
     for i in 0..<L: a[Idx(i + xa)] = b[i]
   else:
-    sysFatal(RangeDefect, "different lengths for slice assignment")
+    when declared(sysFatal):
+      sysFatal(RangeDefect, "different lengths for slice assignment")
+    else:
+      raise newException(RangeDefect, "different lengths for slice assignment")
 
 proc `[]`*[T; U, V: Ordinal](s: openArray[T], x: HSlice[U, V]): seq[T] {.systemRaisesDefect.} =
   ## Slice operation for sequences.
diff --git a/lib/system/integerops.nim b/lib/system/integerops.nim
index 22875b330d704..1816a0a8b885e 100644
--- a/lib/system/integerops.nim
+++ b/lib/system/integerops.nim
@@ -12,10 +12,16 @@
 
 proc raiseOverflow {.compilerproc, noinline.} =
   # a single proc to reduce code size to a minimum
-  sysFatal(OverflowDefect, "over- or underflow")
+  when declared(sysFatal):
+    sysFatal(OverflowDefect, "over- or underflow")
+  else:
+    raise newException(OverflowDefect, "over- or underflow")
 
 proc raiseDivByZero {.compilerproc, noinline.} =
-  sysFatal(DivByZeroDefect, "division by zero")
+  when declared(sysFatal):
+    sysFatal(DivByZeroDefect, "division by zero")
+  else:
+    raise newException(DivByZeroDefect, "division by zero")
 
 {.pragma: nimbaseH, importc, nodecl, noSideEffect, compilerproc.}
 
@@ -124,10 +130,19 @@ divImplFallback(nimDivInt, int)
 divImplFallback(nimDivInt64, int64)
 
 proc raiseFloatInvalidOp {.compilerproc, noinline.} =
-  sysFatal(FloatInvalidOpDefect, "FPU operation caused a NaN result")
+  when declared(sysFatal):
+    sysFatal(FloatInvalidOpDefect, "FPU operation caused a NaN result")
+  else:
+    raise newException(FloatInvalidOpDefect, "FPU operation caused a NaN result")
 
 proc raiseFloatOverflow(x: float64) {.compilerproc, noinline.} =
   if x > 0.0:
-    sysFatal(FloatOverflowDefect, "FPU operation caused an overflow")
+    when declared(sysFatal):
+      sysFatal(FloatOverflowDefect, "FPU operation caused an overflow")
+    else:
+      raise newException(FloatOverflowDefect, "FPU operation caused an overflow")
   else:
-    sysFatal(FloatUnderflowDefect, "FPU operations caused an underflow")
+    when declared(sysFatal):
+      sysFatal(FloatUnderflowDefect, "FPU operations caused an underflow")
+    else:
+      raise newException(FloatUnderflowDefect, "FPU operations caused an underflow")
diff --git a/tests/errmsgs/t14444.nim b/tests/errmsgs/t14444.nim
index 27365236ed5ac..f9bef08d80be8 100644
--- a/tests/errmsgs/t14444.nim
+++ b/tests/errmsgs/t14444.nim
@@ -3,7 +3,7 @@ discard """
   exitcode: "1"
   output: '''
 t14444.nim(13)           t14444
-fatal.nim(53)            sysFatal
+fatal.nim(63)            sysFatal
 Error: unhandled exception: index out of bounds, the container is empty [IndexDefect]
 '''
 """
diff --git a/tests/errmsgs/t23536.nim b/tests/errmsgs/t23536.nim
index d8f143333132f..654e92490faa1 100644
--- a/tests/errmsgs/t23536.nim
+++ b/tests/errmsgs/t23536.nim
@@ -8,7 +8,7 @@ t23536.nim(22)           t23536
 t23536.nim(17)           foo
 assertions.nim(45)       failedAssertImpl
 assertions.nim(40)       raiseAssert
-fatal.nim(53)            sysFatal
+fatal.nim(63)            sysFatal
 """
 
 
diff --git a/tests/errmsgs/t24974.nim b/tests/errmsgs/t24974.nim
index 39d473a89e343..4f98e49f62db2 100644
--- a/tests/errmsgs/t24974.nim
+++ b/tests/errmsgs/t24974.nim
@@ -6,7 +6,7 @@ t24974.nim(19)           d
 t24974.nim(16)           s
 assertions.nim(45)       failedAssertImpl
 assertions.nim(40)       raiseAssert
-fatal.nim(53)            sysFatal
+fatal.nim(63)            sysFatal
 Error: unhandled exception: t24974.nim(16, 26) `false`  [AssertionDefect]
 '''
 """
diff --git a/tests/exception/t22469.nim b/tests/exception/t22469.nim
index a76c749678c2c..c0752aeba3b76 100644
--- a/tests/exception/t22469.nim
+++ b/tests/exception/t22469.nim
@@ -3,7 +3,7 @@ discard """
   output: '''
 First top-level statement of ModuleB
 m22469.nim(3)            m22469
-fatal.nim(53)            sysFatal
+fatal.nim(63)            sysFatal
 Error: unhandled exception: over- or underflow [OverflowDefect]
 '''
 """