diff --git a/SheepShaver/src/Unix/sysdeps.h b/SheepShaver/src/Unix/sysdeps.h
index 1a96daba..766e74ee 100644
--- a/SheepShaver/src/Unix/sysdeps.h
+++ b/SheepShaver/src/Unix/sysdeps.h
@@ -166,6 +166,12 @@ typedef int64 intptr;
 #error "Unsupported size of pointer"
 #endif
 
+// Define if the host processor supports fast unaligned load/stores
+#if defined __i386__ || defined __x86_64__
+#define UNALIGNED_PROFITABLE 1
+#endif
+
+
 /**
  *		Helper functions to byteswap data
  **/
diff --git a/SheepShaver/src/Windows/sysdeps.h b/SheepShaver/src/Windows/sysdeps.h
index b9b9f107..5b9f9152 100755
--- a/SheepShaver/src/Windows/sysdeps.h
+++ b/SheepShaver/src/Windows/sysdeps.h
@@ -125,6 +125,11 @@ typedef int64 intptr;
 #error "Unsupported size of pointer"
 #endif
 
+// Define if the host processor supports fast unaligned load/stores
+#if defined __i386__ || defined __x86_64__
+#define UNALIGNED_PROFITABLE 1
+#endif
+
 
 /**
  *		Helper functions to byteswap data