diff --git a/src/calls.c b/src/calls.c
index a67d03f646..d2694d39ba 100644
--- a/src/calls.c
+++ b/src/calls.c
@@ -1531,6 +1531,17 @@ Int IsKernelFunction(Obj func)
            (SIZE_OBJ(BODY_FUNC(func)) == sizeof(BodyHeader));
 }
 
+
+/* Returns a measure of the size of a GAP function */
+static Obj FuncFUNC_BODY_SIZE(Obj self, Obj func)
+{
+    RequireFunction("FUNC_BODY_SIZE", func);
+    Obj body = BODY_FUNC(func);
+    if (body == 0)
+        return INTOBJ_INT(0);
+    return ObjInt_UInt(SIZE_BAG(body));
+}
+
 #ifdef USE_GASMAN
 
 static void SaveHandler(ObjFunc hdlr)
@@ -1671,7 +1682,7 @@ static StructGVarOper GVarOpers [] = {
 **
 *V  GVarFuncs . . . . . . . . . . . . . . . . . . list of functions to export
 */
-static StructGVarFunc GVarFuncs [] = {
+static StructGVarFunc GVarFuncs[] = {
 
     GVAR_FUNC(CLEAR_PROFILE_FUNC, 1, "func"),
     GVAR_FUNC(IS_PROFILED_FUNC, 1, "func"),
@@ -1682,6 +1693,9 @@ static StructGVarFunc GVarFuncs [] = {
     GVAR_FUNC(LOCATION_FUNC, 1, "func"),
     GVAR_FUNC(STARTLINE_FUNC, 1, "func"),
     GVAR_FUNC(ENDLINE_FUNC, 1, "func"),
+
+    GVAR_FUNC(FUNC_BODY_SIZE, 1, "func"),
+
     { 0, 0, 0, 0, 0 }
 
 };
diff --git a/src/gap.c b/src/gap.c
index 5e0b745535..409df5a3cf 100644
--- a/src/gap.c
+++ b/src/gap.c
@@ -1080,7 +1080,7 @@ static Obj FuncTNAM_OBJ(Obj self, Obj obj)
 */
 static Obj FuncOBJ_HANDLE(Obj self, Obj handle)
 {
-    if (handle != INTPOST_INT(0) && !IS_POS_INT(handle))
+    if (handle != INTOBJ_INT(0) && !IS_POS_INT(handle))
         RequireArgument("OBJ_HANDLE", handle,
                         "must be a non-negative integer");
     return (Obj)UInt_ObjInt(handle);
@@ -1123,16 +1123,6 @@ static Obj FuncMASTER_POINTER_NUMBER(Obj self, Obj o)
 #endif
 }
 
-/* Returns a measure of the size of a GAP function */
-static Obj FuncFUNC_BODY_SIZE(Obj self, Obj f)
-{
-    Obj body;
-    if (TNUM_OBJ(f) != T_FUNCTION) return Fail;
-    body = BODY_FUNC(f);
-    if (body == 0) return INTOBJ_INT(0);
-    else return ObjInt_UInt( SIZE_BAG( body ) );
-}
-
 /****************************************************************************
 **
 *F  FuncSleep( <self>, <secs> )
@@ -1525,7 +1515,6 @@ static StructGVarFunc GVarFuncs[] = {
     GVAR_FUNC(THREAD_UI, 0, ""),
 #endif
     GVAR_FUNC(MASTER_POINTER_NUMBER, 1, "ob"),
-    GVAR_FUNC(FUNC_BODY_SIZE, 1, "f"),
     GVAR_FUNC(BREAKPOINT, 1, "integer"),
     GVAR_FUNC(UPDATE_STAT, 2, "string, object"),
     { 0, 0, 0, 0, 0 }
diff --git a/tst/testinstall/kernel/gap.tst b/tst/testinstall/kernel/gap.tst
index fba24c1800..334d4cecf0 100644
--- a/tst/testinstall/kernel/gap.tst
+++ b/tst/testinstall/kernel/gap.tst
@@ -164,7 +164,9 @@ gap> MASTER_POINTER_NUMBER(Z(2));
 
 #
 gap> FUNC_BODY_SIZE(fail);
-fail
+Error, FUNC_BODY_SIZE: <func> must be a function (not the value 'fail')
+gap> FUNC_BODY_SIZE(SHELL) / GAPInfo.BytesPerVariable;
+4
 
 #
 gap> Sleep(fail);