diff --git a/docs/lang/preprocessor.md b/docs/lang/preprocessor.md
index e0e5d266..275365d3 100644
--- a/docs/lang/preprocessor.md
+++ b/docs/lang/preprocessor.md
@@ -57,6 +57,10 @@ The following features are defined based on the chosen CPU and compilation optio
 * `INIT_RW_MEMORY` – 1 if the option `ram_init_segment` is defined, 0 otherwise.
 See [the ROM vs RAM guide](../api/rom-vs-ram.md) for more information.
 
+* `BIG_ENDIAN` – 1 if the platform is big-endian, 0 otherwise (currently all supported platforms are little-endian)
+
+* `LITTLE_ENDIAN` – 1 if the platform is little-endian, 0 otherwise (currently all supported platforms are little-endian)
+
 * `OPTIMIZE_FOR_SIZE`, `OPTIMIZE_FOR_SPEED`, `OPTIMIZE_INLINE`, `OPTIMIZE_IPO`
 – 1 if given optimization setting is enabled, 0 otherwise
 
diff --git a/src/main/scala/millfork/CompilationOptions.scala b/src/main/scala/millfork/CompilationOptions.scala
index e7e59c1f..17faf7b7 100644
--- a/src/main/scala/millfork/CompilationOptions.scala
+++ b/src/main/scala/millfork/CompilationOptions.scala
@@ -214,6 +214,8 @@ case class CompilationOptions(platform: Platform,
       "CPUFEATURE_6502_ILLEGALS" -> toLong(platform.cpuFamily == CpuFamily.M6502 && flag(CompilationFlag.EmitIllegals)),
       "CPUFEATURE_Z80_ILLEGALS" -> toLong(flag(CompilationFlag.EmitZ80Opcodes) && flag(CompilationFlag.EmitIllegals)),
       "CPUFEATURE_8085_ILLEGALS" -> toLong(flag(CompilationFlag.EmitIntel8080Opcodes) && flag(CompilationFlag.EmitIllegals)),
+      "BIG_ENDIAN" -> toLong(Cpu.isBigEndian(platform.cpu)),
+      "LITTLE_ENDIAN" -> toLong(!Cpu.isBigEndian(platform.cpu)),
       "INIT_RW_MEMORY" -> toLong(platform.ramInitialValuesBank.isDefined),
       "SYNTAX_INTEL" -> toLong(platform.cpuFamily == CpuFamily.I80 && flag(CompilationFlag.UseIntelSyntaxForInput)),
       "SYNTAX_ZILOG" -> toLong(platform.cpuFamily == CpuFamily.I80 && !flag(CompilationFlag.UseIntelSyntaxForInput)),
@@ -269,6 +271,11 @@ object CpuFamily extends Enumeration {
       case Cpu.Motorola6809 => M6809
     }
   }
+
+  def isBigEndian(family: CpuFamily.Value): Boolean = family match {
+    case M6502 | I80 | I86 | ARM => false
+    case M6800 | M6809 | M68K => true
+  }
 }
 
 object Cpu extends Enumeration {
@@ -475,6 +482,8 @@ object Cpu extends Enumeration {
       case CpuFamily.M6809 => 2
       case _ => ???
     }
+
+  def isBigEndian(cpu: Cpu.Value): Boolean = CpuFamily.isBigEndian(CpuFamily.forType(cpu))
 }
 
 object CompilationFlag extends Enumeration {