diff --git a/libgnucash/engine/CMakeLists.txt b/libgnucash/engine/CMakeLists.txt
index 6fc7f8b118..46874ad740 100644
--- a/libgnucash/engine/CMakeLists.txt
+++ b/libgnucash/engine/CMakeLists.txt
@@ -147,7 +147,7 @@ set (engine_SOURCES
   Scrub3.c
   ScrubBusiness.c
   ScrubBudget.c
-  Split.c
+  Split.cpp
   TransLog.c
   Transaction.c
   cap-gains.c
diff --git a/libgnucash/engine/Split.c b/libgnucash/engine/Split.cpp
similarity index 98%
rename from libgnucash/engine/Split.c
rename to libgnucash/engine/Split.cpp
index 0272b020a5..2da0c51b9f 100644
--- a/libgnucash/engine/Split.c
+++ b/libgnucash/engine/Split.cpp
@@ -242,25 +242,25 @@ gnc_split_set_property(GObject         *object,
             xaccSplitSetMemo(split, g_value_get_string(value));
             break;
         case PROP_VALUE:
-            number = g_value_get_boxed(value);
+            number = static_cast<gnc_numeric*>(g_value_get_boxed(value));
             xaccSplitSetValue(split, *number);
             break;
         case PROP_AMOUNT:
-            number = g_value_get_boxed(value);
+            number = static_cast<gnc_numeric*>(g_value_get_boxed(value));
             xaccSplitSetAmount(split, *number);
             break;
         case PROP_RECONCILE_DATE:
-            t = g_value_get_boxed(value);
+            t = static_cast<Time64*>(g_value_get_boxed(value));
             xaccSplitSetDateReconciledSecs(split, t->t);
             break;
         case PROP_TX:
-            xaccSplitSetParent(split, g_value_get_object(value));
+            xaccSplitSetParent(split, GNC_TRANSACTION(g_value_get_object(value)));
             break;
         case PROP_ACCOUNT:
-            xaccSplitSetAccount(split, g_value_get_object(value));
+            xaccSplitSetAccount(split, GNC_ACCOUNT(g_value_get_object(value)));
             break;
         case PROP_LOT:
-            xaccSplitSetLot(split, g_value_get_object(value));
+            xaccSplitSetLot(split, GNC_LOT(g_value_get_object(value)));
             break;
         case PROP_SX_CREDIT_FORMULA:
             qof_instance_set_kvp (QOF_INSTANCE (split), value, 2, GNC_SX_ID, GNC_SX_CREDIT_FORMULA);
@@ -532,7 +532,7 @@ xaccMallocSplit(QofBook *book)
     Split *split;
     g_return_val_if_fail (book, NULL);
 
-    split = g_object_new (GNC_TYPE_SPLIT, NULL);
+    split = GNC_SPLIT(g_object_new (GNC_TYPE_SPLIT, NULL));
     xaccInitSplit (split, book);
 
     return split;
@@ -550,7 +550,7 @@ xaccMallocSplit(QofBook *book)
 Split *
 xaccDupeSplit (const Split *s)
 {
-    Split *split = g_object_new (GNC_TYPE_SPLIT, NULL);
+    Split *split = GNC_SPLIT(g_object_new (GNC_TYPE_SPLIT, NULL));
 
     /* Trash the entity table. We don't want to mistake the cloned
      * splits as something official.  If we ever use this split, we'll
@@ -588,7 +588,7 @@ xaccDupeSplit (const Split *s)
 Split *
 xaccSplitCloneNoKvp (const Split *s)
 {
-    Split *split = g_object_new (GNC_TYPE_SPLIT, NULL);
+    Split *split = GNC_SPLIT(g_object_new (GNC_TYPE_SPLIT, NULL));
 
     split->parent              = NULL;
     split->memo                = CACHE_INSERT(s->memo);
@@ -2104,7 +2104,7 @@ xaccSplitGetOtherSplit (const Split *split)
 
     for (GList *n = xaccTransGetSplitList (trans); n; n = n->next)
     {
-        Split *s = n->data;
+        Split *s = GNC_SPLIT(n->data);
         if ((s == split) ||
             (!xaccTransStillHasSplit(trans, s)) ||
             (xaccAccountGetType (xaccSplitGetAccount (s)) == ACCT_TYPE_TRADING) ||
@@ -2203,7 +2203,7 @@ static QofObject split_object_def =
     DI(.interface_version = ) QOF_OBJECT_VERSION,
     DI(.e_type            = ) GNC_ID_SPLIT,
     DI(.type_label        = ) "Split",
-    DI(.create            = ) (gpointer)xaccMallocSplit,
+    DI(.create            = ) (void* (*)(QofBook*))xaccMallocSplit,
     DI(.book_begin        = ) NULL,
     DI(.book_end          = ) NULL,
     DI(.is_dirty          = ) qof_collection_is_dirty,
@@ -2216,7 +2216,7 @@ static QofObject split_object_def =
 static gpointer
 split_account_guid_getter (gpointer obj, const QofParam *p)
 {
-    Split *s = obj;
+    Split *s = GNC_SPLIT(obj);
     Account *acc;
 
     if (!s) return NULL;
diff --git a/libgnucash/engine/test/utest-Split.cpp b/libgnucash/engine/test/utest-Split.cpp
index fbf56fa2ed..a1535ba79d 100644
--- a/libgnucash/engine/test/utest-Split.cpp
+++ b/libgnucash/engine/test/utest-Split.cpp
@@ -35,7 +35,7 @@
 #include <gnc-lot.h>
 #include <gnc-event.h>
 
-#if defined(__clang__) && (__clang_major__ == 5 || (__clang_major__ == 3 && __clang_minor__ < 5))
+#if defined(__clang__)
 #define USE_CLANG_FUNC_SIG 1
 #endif
 
@@ -1282,7 +1282,7 @@ test_get_corr_account_split (Fixture *fixture, gconstpointer pData)
 #ifdef USE_CLANG_FUNC_SIG
 #define _func "gboolean get_corr_account_split(const Split *, const Split **)"
 #else
-#define _func "get_corr_account_split"
+#define _func "gboolean get_corr_account_split(const Split*, const Split**)"
 #endif
     gchar *msg = _func ": assertion 'sa' failed";
 #undef _func
diff --git a/po/POTFILES.in b/po/POTFILES.in
index 94fbc6f70a..f41b3ab493 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -690,7 +690,7 @@ libgnucash/engine/Scrub3.c
 libgnucash/engine/ScrubBudget.c
 libgnucash/engine/ScrubBusiness.c
 libgnucash/engine/Scrub.c
-libgnucash/engine/Split.c
+libgnucash/engine/Split.cpp
 libgnucash/engine/SX-book.c
 libgnucash/engine/SX-ttinfo.c
 libgnucash/engine/Transaction.c