--- a/ExternalFunctionCallback.st	Mon Feb 19 14:59:40 2018 +0100
+++ b/ExternalFunctionCallback.st	Mon Feb 19 16:01:21 2018 +0100
@@ -565,6 +565,7 @@
     int i;
     ffi_abi __callType = FFI_DEFAULT_ABI;
     int __numArgsWanted;
+#ifdef OLD_FFI
     struct closurePlusCIF {
         ffi_closure closure;
         ffi_cif cif;
@@ -573,17 +574,33 @@
     ffi_closure *pcl;
     ffi_cif *cif;
     ffi_type **argTypePtrs;
+#else
+    ffi_closure *closure;
+    void* codePtr;
+    ffi_cif _cif;
+    ffi_cif *cif = &_cif;
+    ffi_type *argTypes[MAX_ARGS];
+#endif
 
+#ifdef OLD_FFI
     closurePlusCIFp = (struct closurePlusCIF *) malloc(sizeof(struct closurePlusCIF));
-    cif = &(closurePlusCIFp->cif);
-    argTypePtrs = closurePlusCIFp->argTypes;
-    pcl = &(closurePlusCIFp->closure);
-
+    codePtr = &(closurePlusCIFp->closure);
 #   define __FAIL__(fcode) \
         { \
             failureCode = fcode; free(closurePlusCIFp); goto getOutOfHere; \
         }
 
+#else
+    closurePlusCIFp = (struct closurePlusCIF *) ffi_closure_alloc(sizeof(struct closurePlusCIF), &codePtr);
+#   define __FAIL__(fcode) \
+        { \
+            failureCode = fcode; ffi_closure_free(closure); goto getOutOfHere; \
+        }
+#endif
+    pcl = &(closurePlusCIFp->closure);
+    cif = &(closurePlusCIFp->cif);
+    argTypePtrs = closurePlusCIFp->argTypes;
+
     if (argTypeSymbols == nil) {
         __numArgsWanted = 0;
     } else if (__isArrayLike(argTypeSymbols)) {
@@ -770,7 +787,7 @@
             __FAIL__(@symbol(UnknownArgumentType))
         }
 
-        closurePlusCIFp->argTypes[i] = thisType;
+        argTypePtrs[i] = thisType;
     }
     failureInfo = nil;
 
@@ -800,7 +817,7 @@
     }
 #endif
     if (@global(ExternalFunctionCallback:Verbose) == true) {
-        printf("prep_cif cif-ptr=%"_lx_"\n", (INT)cif);
+        printf("prep_cif callType:%d cif-ptr=%p\n", __callType, (INT)cif);
     }
 
     if (ffi_prep_cif(cif, __callType, __numArgsWanted, __returnType, argTypePtrs) != FFI_OK) {
@@ -811,9 +828,15 @@
         printf("closure is 0x%"_lx_" (%d bytes)\n", (INT)pcl, (int)sizeof(ffi_closure));
         printf("index is %"_ld_"\n", __intVal(callBackIndex));
     }
+#ifdef OLD_FFI
     if (ffi_prep_closure(pcl, cif, ExternalFunctionCallback__closure_wrapper_fn, (void *)(__intVal(callBackIndex)) /* userdata */) != FFI_OK) {
         __FAIL__(@symbol(FFIPrepareClosureFailed))
     }
+#else
+    if (ffi_prep_closure_loc(pcl, cif, ExternalFunctionCallback__closure_wrapper_fn, (void *)(__intVal(callBackIndex), codePtr)) != FFI_OK) {
+        __FAIL__(@symbol(FFIPrepareClosureFailed))
+    }
+#endif
     if (@global(ExternalFunctionCallback:Verbose) == true) {
         printf("pcl->cif is 0x%"_lx_"\n", (INT)(pcl->cif));
         printf("pcl->fun is 0x%"_lx_"\n", (INT)(pcl->fun));