diff --git a/bootstrap/unix-44/SYSTEM.h b/bootstrap/unix-44/SYSTEM.h
index 35ca975e..130a7f9b 100644
--- a/bootstrap/unix-44/SYSTEM.h
+++ b/bootstrap/unix-44/SYSTEM.h
@@ -32,7 +32,7 @@ typedef unsigned char        SYSTEM_CARD8;
   typedef unsigned int         size_t;
 #endif
 
-void * __cdecl memcpy(void *dest, const void *source, size_t size);
+void *memcpy(void *dest, const void *source, size_t size);
 
 
 
diff --git a/bootstrap/unix-48/SYSTEM.h b/bootstrap/unix-48/SYSTEM.h
index 35ca975e..130a7f9b 100644
--- a/bootstrap/unix-48/SYSTEM.h
+++ b/bootstrap/unix-48/SYSTEM.h
@@ -32,7 +32,7 @@ typedef unsigned char        SYSTEM_CARD8;
   typedef unsigned int         size_t;
 #endif
 
-void * __cdecl memcpy(void *dest, const void *source, size_t size);
+void *memcpy(void *dest, const void *source, size_t size);
 
 
 
diff --git a/bootstrap/unix-88/SYSTEM.h b/bootstrap/unix-88/SYSTEM.h
index 35ca975e..130a7f9b 100644
--- a/bootstrap/unix-88/SYSTEM.h
+++ b/bootstrap/unix-88/SYSTEM.h
@@ -32,7 +32,7 @@ typedef unsigned char        SYSTEM_CARD8;
   typedef unsigned int         size_t;
 #endif
 
-void * __cdecl memcpy(void *dest, const void *source, size_t size);
+void *memcpy(void *dest, const void *source, size_t size);
 
 
 
diff --git a/bootstrap/windows-48/SYSTEM.h b/bootstrap/windows-48/SYSTEM.h
index 35ca975e..130a7f9b 100644
--- a/bootstrap/windows-48/SYSTEM.h
+++ b/bootstrap/windows-48/SYSTEM.h
@@ -32,7 +32,7 @@ typedef unsigned char        SYSTEM_CARD8;
   typedef unsigned int         size_t;
 #endif
 
-void * __cdecl memcpy(void *dest, const void *source, size_t size);
+void *memcpy(void *dest, const void *source, size_t size);
 
 
 
diff --git a/bootstrap/windows-88/SYSTEM.h b/bootstrap/windows-88/SYSTEM.h
index 35ca975e..130a7f9b 100644
--- a/bootstrap/windows-88/SYSTEM.h
+++ b/bootstrap/windows-88/SYSTEM.h
@@ -32,7 +32,7 @@ typedef unsigned char        SYSTEM_CARD8;
   typedef unsigned int         size_t;
 #endif
 
-void * __cdecl memcpy(void *dest, const void *source, size_t size);
+void *memcpy(void *dest, const void *source, size_t size);
 
 
 
diff --git a/src/system/SYSTEM.h b/src/system/SYSTEM.h
index 35ca975e..130a7f9b 100644
--- a/src/system/SYSTEM.h
+++ b/src/system/SYSTEM.h
@@ -32,7 +32,7 @@ typedef unsigned char        SYSTEM_CARD8;
   typedef unsigned int         size_t;
 #endif
 
-void * __cdecl memcpy(void *dest, const void *source, size_t size);
+void *memcpy(void *dest, const void *source, size_t size);