diff --git a/arm64-gen.c b/arm64-gen.c
index 5ea47db4..35538d1a 100644
--- a/arm64-gen.c
+++ b/arm64-gen.c
@@ -40,6 +40,9 @@
 
 #define CHAR_IS_UNSIGNED
 
+/* define if return values need to be extended explicitely
+   at caller side (for interfacing with non-TCC compilers) */
+#define PROMOTE_RET
 /******************************************************/
 #else /* ! TARGET_DEFS_ONLY */
 /******************************************************/
diff --git a/i386-gen.c b/i386-gen.c
index 8b81c66f..7e1e0f49 100644
--- a/i386-gen.c
+++ b/i386-gen.c
@@ -71,6 +71,10 @@ enum {
 /* maximum alignment (for aligned attribute support) */
 #define MAX_ALIGN     8
 
+/* define if return values need to be extended explicitely
+   at caller side (for interfacing with non-TCC compilers) */
+#define PROMOTE_RET
+
 /******************************************************/
 #else /* ! TARGET_DEFS_ONLY */
 /******************************************************/
diff --git a/tccgen.c b/tccgen.c
index 0475b3c5..0f3d96ec 100644
--- a/tccgen.c
+++ b/tccgen.c
@@ -5631,10 +5631,18 @@ special_math_val:
                 }
 
                 /* Promote char/short return values. This is matters only
-                   for calling function that were not compiled by TCC */
+                   for calling function that were not compiled by TCC and
+                   only on some architectures.  For those where it doesn't
+                   matter we expect things to be already promoted to int,
+                   but not larger.  */
                 t = s->type.t & VT_BTYPE;
-                if (t == VT_BYTE || t == VT_SHORT || t == VT_BOOL)
+                if (t == VT_BYTE || t == VT_SHORT || t == VT_BOOL) {
+#ifdef PROMOTE_RET
                     vtop->r |= BFVAL(VT_MUSTCAST, 1);
+#else
+                    vtop->type.t = VT_INT;
+#endif
+                }
             }
             if (s->f.func_noreturn)
                 CODE_OFF();
diff --git a/tests/tcctest.c b/tests/tcctest.c
index 15d849ca..373eb952 100644
--- a/tests/tcctest.c
+++ b/tests/tcctest.c
@@ -1210,13 +1210,7 @@ void struct_test()
 /* simulate char/short return value with undefined upper bits */
 static int __csf(int x) { return x; }
 static void *_csf = __csf;
-#ifdef __TINYC__
 #define csf(t,n) ((t(*)(int))_csf)(n)
-#define csfb csf
-#else /* arm gcc maybe doesn't promote function return values */
-#define csf(t,n) (t) n
-#define csfb(t,n) (t) (n & 255)
-#endif
 
 /* XXX: depend on endianness */
 void char_short_test()
@@ -1257,14 +1251,18 @@ void char_short_test()
     var4 = 0x11223344aa998877ULL;
     printf("promote char/short assign VA %d %d\n", var3 = var1 + 1, var3 = var4 + 1);
     printf("promote char/short cast VA %d %d\n", (char)(var1 + 1), (char)(var4 + 1));
+#if !defined(__arm__)
+    /* We can't really express GCC behaviour of return type promotion in
+       the presence of undefined behaviour (like __csf is).  */
     var1 = csf(unsigned char,0x89898989);
     var4 = csf(signed char,0xabababab);
     printf("promote char/short funcret %d "LONG_LONG_FORMAT"\n", var1, var4);
     printf("promote char/short fumcret VA %d %d %d %d\n",
         csf(unsigned short,0xcdcdcdcd),
         csf(short,0xefefefef),
-        csfb(_Bool,0x33221100),
-        csfb(_Bool,0x33221101));
+        csf(_Bool,0x33221100),
+        csf(_Bool,0x33221101));
+#endif
     var3 = -10;
     var1 = (char)(unsigned char)(var3 + 1);
     var4 = (char)(unsigned char)(var3 + 1);
diff --git a/x86_64-gen.c b/x86_64-gen.c
index fd2d6936..439fd988 100644
--- a/x86_64-gen.c
+++ b/x86_64-gen.c
@@ -102,6 +102,9 @@ enum {
 /* maximum alignment (for aligned attribute support) */
 #define MAX_ALIGN     16
 
+/* define if return values need to be extended explicitely
+   at caller side (for interfacing with non-TCC compilers) */
+#define PROMOTE_RET
 /******************************************************/
 #else /* ! TARGET_DEFS_ONLY */
 /******************************************************/