diff --git a/src/import-export/aqbanking/dialog-ab-trans.c b/src/import-export/aqbanking/dialog-ab-trans.c
index fcd9c153d7..198b10fda0 100644
--- a/src/import-export/aqbanking/dialog-ab-trans.c
+++ b/src/import-export/aqbanking/dialog-ab-trans.c
@@ -646,7 +646,11 @@ get_available_empty_job(AB_ACCOUNT *ab_acc, GncABTransType trans_type)
         job = AB_JobSingleTransfer_new(ab_acc);
     };
 
-    if (!job || AB_Job_CheckAvailability(job, 0))
+    if (!job || AB_Job_CheckAvailability(job
+#ifndef AQBANKING_VERSION_5_PLUS
+                                         , 0
+#endif
+            ))
     {
         if (job) AB_Job_free(job);
         return NULL;
diff --git a/src/import-export/aqbanking/druid-ab-initial.c b/src/import-export/aqbanking/druid-ab-initial.c
index 3c3e2f171f..a4daca2870 100644
--- a/src/import-export/aqbanking/druid-ab-initial.c
+++ b/src/import-export/aqbanking/druid-ab-initial.c
@@ -174,7 +174,7 @@ dai_destroy_cb(GtkObject *object, gpointer user_data)
 
     if (info->gnc_hash)
     {
-#ifdef AQBANKING_VERSION_4_PLUS
+#ifdef AQBANKING_VERSION_4_EXACTLY
         AB_Banking_OnlineFini(info->api, 0);
 #else
         AB_Banking_OnlineFini(info->api);
@@ -352,7 +352,7 @@ dai_match_page_prepare_cb(GnomeDruidPage *druid_page, GtkWidget *widget,
         info->match_page_prepared = TRUE;
 
     /* Load aqbanking accounts */
-#ifdef AQBANKING_VERSION_4_PLUS
+#ifdef AQBANKING_VERSION_4_EXACTLY
     AB_Banking_OnlineInit(info->api, 0);
 #else
     AB_Banking_OnlineInit(info->api);
@@ -395,7 +395,7 @@ banking_has_accounts(AB_BANKING *banking)
 
     g_return_val_if_fail(banking, FALSE);
 
-#ifdef AQBANKING_VERSION_4_PLUS
+#ifdef AQBANKING_VERSION_4_EXACTLY
     AB_Banking_OnlineInit(banking, 0);
 #else
     AB_Banking_OnlineInit(banking);
@@ -410,7 +410,7 @@ banking_has_accounts(AB_BANKING *banking)
     if (accl)
         AB_Account_List2_free(accl);
 
-#ifdef AQBANKING_VERSION_4_PLUS
+#ifdef AQBANKING_VERSION_4_EXACTLY
     AB_Banking_OnlineFini(banking, 0);
 #else
     AB_Banking_OnlineFini(banking);
diff --git a/src/import-export/aqbanking/gnc-ab-getbalance.c b/src/import-export/aqbanking/gnc-ab-getbalance.c
index 3afa46740f..e0364e0d13 100644
--- a/src/import-export/aqbanking/gnc-ab-getbalance.c
+++ b/src/import-export/aqbanking/gnc-ab-getbalance.c
@@ -64,7 +64,7 @@ gnc_ab_getbalance(GtkWidget *parent, Account *gnc_acc)
         return;
     }
     if (AB_Banking_OnlineInit(api
-#ifdef AQBANKING_VERSION_4_PLUS
+#ifdef AQBANKING_VERSION_4_EXACTLY
                               , 0
 #endif
                              ) != 0)
@@ -84,7 +84,11 @@ gnc_ab_getbalance(GtkWidget *parent, Account *gnc_acc)
 
     /* Get a GetBalance job and enqueue it */
     job = AB_JobGetBalance_new(ab_acc);
-    if (!job || AB_Job_CheckAvailability(job, 0))
+    if (!job || AB_Job_CheckAvailability(job
+#ifndef AQBANKING_VERSION_5_PLUS
+                                         , 0
+#endif
+            ))
     {
         g_warning("gnc_ab_getbalance: JobGetBalance not available for this "
                   "account");
@@ -105,7 +109,11 @@ gnc_ab_getbalance(GtkWidget *parent, Account *gnc_acc)
     context = AB_ImExporterContext_new();
 
     /* Execute the job */
-    if (AB_Banking_ExecuteJobs(api, job_list, context, 0))
+    if (AB_Banking_ExecuteJobs(api, job_list, context
+#ifndef AQBANKING_VERSION_5_PLUS
+                               , 0
+#endif
+            ))
     {
         g_warning("gnc_ab_getbalance: Error on executing job");
         goto cleanup;
@@ -126,7 +134,7 @@ cleanup:
     if (job)
         AB_Job_free(job);
     if (online)
-#ifdef AQBANKING_VERSION_4_PLUS
+#ifdef AQBANKING_VERSION_4_EXACTLY
         AB_Banking_OnlineFini(api, 0);
 #else
         AB_Banking_OnlineFini(api);
diff --git a/src/import-export/aqbanking/gnc-ab-gettrans.c b/src/import-export/aqbanking/gnc-ab-gettrans.c
index 7d3c9eca43..a5c76360b6 100644
--- a/src/import-export/aqbanking/gnc-ab-gettrans.c
+++ b/src/import-export/aqbanking/gnc-ab-gettrans.c
@@ -117,7 +117,7 @@ gnc_ab_gettrans(GtkWidget *parent, Account *gnc_acc)
         return;
     }
     if (AB_Banking_OnlineInit(api
-#ifdef AQBANKING_VERSION_4_PLUS
+#ifdef AQBANKING_VERSION_4_EXACTLY
                               , 0
 #endif
                              ) != 0)
@@ -146,7 +146,11 @@ gnc_ab_gettrans(GtkWidget *parent, Account *gnc_acc)
 
     /* Get a GetTransactions job and enqueue it */
     job = AB_JobGetTransactions_new(ab_acc);
-    if (!job || AB_Job_CheckAvailability(job, 0))
+    if (!job || AB_Job_CheckAvailability(job
+#ifndef AQBANKING_VERSION_5_PLUS
+                                         , 0
+#endif
+            ))
     {
         g_warning("gnc_ab_gettrans: JobGetTransactions not available for this "
                   "account");
@@ -169,7 +173,11 @@ gnc_ab_gettrans(GtkWidget *parent, Account *gnc_acc)
     context = AB_ImExporterContext_new();
 
     /* Execute the job */
-    if (AB_Banking_ExecuteJobs(api, job_list, context, 0))
+    if (AB_Banking_ExecuteJobs(api, job_list, context
+#ifndef AQBANKING_VERSION_5_PLUS
+                               , 0
+#endif
+            ))
     {
         g_warning("gnc_ab_gettrans: Error on executing job");
         goto cleanup;
@@ -212,7 +220,7 @@ cleanup:
     if (from_date)
         GWEN_Time_free(from_date);
     if (online)
-#ifdef AQBANKING_VERSION_4_PLUS
+#ifdef AQBANKING_VERSION_4_EXACTLY
         AB_Banking_OnlineFini(api, 0);
 #else
         AB_Banking_OnlineFini(api);
diff --git a/src/import-export/aqbanking/gnc-ab-transfer.c b/src/import-export/aqbanking/gnc-ab-transfer.c
index 1643fd393e..2367b2a4fc 100644
--- a/src/import-export/aqbanking/gnc-ab-transfer.c
+++ b/src/import-export/aqbanking/gnc-ab-transfer.c
@@ -100,7 +100,7 @@ gnc_ab_maketrans(GtkWidget *parent, Account *gnc_acc,
         return;
     }
     if (AB_Banking_OnlineInit(api
-#ifdef AQBANKING_VERSION_4_PLUS
+#ifdef AQBANKING_VERSION_4_EXACTLY
                               , 0
 #endif
                              ) != 0)
@@ -175,7 +175,11 @@ gnc_ab_maketrans(GtkWidget *parent, Account *gnc_acc,
         /* Get a job and enqueue it */
         ab_trans = gnc_ab_trans_dialog_get_ab_trans(td);
         job = gnc_ab_trans_dialog_get_job(td);
-        if (!job || AB_Job_CheckAvailability(job, 0))
+        if (!job || AB_Job_CheckAvailability(job
+#ifndef AQBANKING_VERSION_5_PLUS
+                                             , 0
+#endif
+                ))
         {
             if (!gnc_verify_dialog(
                         parent, FALSE, "%s",
@@ -256,7 +260,11 @@ gnc_ab_maketrans(GtkWidget *parent, Account *gnc_acc,
             }
 
             /* Finally, execute the job */
-            AB_Banking_ExecuteJobs(api, job_list, context, 0);
+            AB_Banking_ExecuteJobs(api, job_list, context
+#ifndef AQBANKING_VERSION_5_PLUS
+                                   , 0
+#endif
+                );
 
             /* Ignore the return value of AB_Banking_ExecuteJobs(), as the job's
              * status always describes better whether the job was actually
@@ -327,7 +335,7 @@ cleanup:
     if (td)
         gnc_ab_trans_dialog_free(td);
     if (online)
-#ifdef AQBANKING_VERSION_4_PLUS
+#ifdef AQBANKING_VERSION_4_EXACTLY
         AB_Banking_OnlineFini(api, 0);
 #else
         AB_Banking_OnlineFini(api);
diff --git a/src/import-export/aqbanking/gnc-ab-utils.c b/src/import-export/aqbanking/gnc-ab-utils.c
index 0e487ff782..086202d476 100644
--- a/src/import-export/aqbanking/gnc-ab-utils.c
+++ b/src/import-export/aqbanking/gnc-ab-utils.c
@@ -902,7 +902,11 @@ gnc_ab_get_permanent_certs(void)
 
     g_return_val_if_fail(banking, NULL);
 #ifdef AQBANKING_VERSION_4_PLUS
-    rv = AB_Banking_LoadSharedConfig(banking, "certs", &perm_certs, 0);
+    rv = AB_Banking_LoadSharedConfig(banking, "certs", &perm_certs
+# ifndef AQBANKING_VERSION_5_PLUS
+                                     , 0
+# endif
+        );
 #else
     /* FIXME: Add code for older AqBanking versions */
     /* See QBankmanager 0.9.50 in src/kbanking/libs/kbanking.cpp lines 323ff
diff --git a/src/import-export/aqbanking/gnc-ab-utils.h b/src/import-export/aqbanking/gnc-ab-utils.h
index 6ad3522641..f9ed5b85e9 100644
--- a/src/import-export/aqbanking/gnc-ab-utils.h
+++ b/src/import-export/aqbanking/gnc-ab-utils.h
@@ -48,6 +48,17 @@ G_BEGIN_DECLS
 # define AQBANKING_VERSION_4_PLUS
 #endif
 
+#if (AQBANKING_VERSION_MAJOR > 4) || \
+  ((AQBANKING_VERSION_MAJOR == 4) && \
+    (AQBANKING_VERSION_MINOR >= 99))
+/** Defined if libaqbanking5 as opposed to libaqbanking4 is being used */
+# define AQBANKING_VERSION_5_PLUS
+#endif
+
+#if defined(AQBANKING_VERSION_4_PLUS) && !defined(AQBANKING_VERSION_5_PLUS)
+# define AQBANKING_VERSION_4_EXACTLY
+#endif
+
 #define GCONF_SECTION_AQBANKING "dialogs/import/hbci"
 #define KEY_FORMAT_SWIFT940 "format_swift_mt940"
 #define KEY_FORMAT_SWIFT942 "format_swift_mt942"
diff --git a/src/import-export/aqbanking/gnc-file-aqb-import.c b/src/import-export/aqbanking/gnc-file-aqb-import.c
index 31f8c9f8fe..94b63a8c96 100644
--- a/src/import-export/aqbanking/gnc-file-aqb-import.c
+++ b/src/import-export/aqbanking/gnc-file-aqb-import.c
@@ -36,12 +36,20 @@
 #include <glib/gstdio.h>
 #include <fcntl.h>
 #include <unistd.h>
-#include <gwenhywfar/io_file.h>
-#include <gwenhywfar/io_buffered.h>
-#include <gwenhywfar/iomanager.h>
 
-#include "dialog-ab-trans.h"
 #include "gnc-ab-utils.h"
+
+#ifdef AQBANKING_VERSION_5_PLUS
+# include <gwenhywfar/syncio_file.h>
+# include <gwenhywfar/syncio_buffered.h>
+typedef GWEN_SYNCIO GWEN_IO_LAYER;
+#else
+# include <gwenhywfar/io_file.h>
+# include <gwenhywfar/io_buffered.h>
+# include <gwenhywfar/iomanager.h>
+#endif
+
+#include "dialog-ab-trans.h"
 #include "gnc-file.h"
 #include "gnc-file-aqb-import.h"
 #include "gnc-gwen-gui.h"
@@ -103,7 +111,7 @@ gnc_file_aqbanking_import(const gchar *aqbanking_importername,
         goto cleanup;
     }
     if (AB_Banking_OnlineInit(api
-#ifdef AQBANKING_VERSION_4_PLUS
+#ifdef AQBANKING_VERSION_4_EXACTLY
                               , 0
 #endif
                              ) != 0)
@@ -166,23 +174,36 @@ gnc_file_aqbanking_import(const gchar *aqbanking_importername,
     context = AB_ImExporterContext_new();
 
     /* Wrap file in buffered gwen io */
+#ifdef AQBANKING_VERSION_5_PLUS
+    close(dtaus_fd);
+    io = GWEN_SyncIo_File_new(selected_filename, GWEN_SyncIo_File_CreationMode_OpenExisting);
+#else
     io = GWEN_Io_LayerFile_new(dtaus_fd, -1);
-    dtaus_fd = -1;
     if (GWEN_Io_Manager_RegisterLayer(io))
     {
         g_warning("gnc_file_aqbanking_import: Failed to wrap file");
         goto cleanup;
     }
+#endif
+    dtaus_fd = -1;
 
     /* Run the import */
-    if (AB_ImExporter_Import(importer, context, io, db_profile, 0))
+    if (AB_ImExporter_Import(importer, context, io, db_profile
+#ifndef AQBANKING_VERSION_5_PLUS
+                             , 0
+#endif
+            ))
     {
         g_warning("gnc_file_aqbanking_import: Error on import");
         goto cleanup;
     }
 
     /* Close the file */
+#ifdef AQBANKING_VERSION_5_PLUS
+    GWEN_SyncIo_free(io);
+#else
     GWEN_Io_Layer_free(io);
+#endif
 
     /* Import the results */
     ieci = gnc_ab_import_context(context, AWAIT_TRANSACTIONS,
@@ -214,7 +235,7 @@ cleanup:
     if (gui)
         gnc_GWEN_Gui_release(gui);
     if (online)
-#ifdef AQBANKING_VERSION_4_PLUS
+#ifdef AQBANKING_VERSION_4_EXACTLY
         AB_Banking_OnlineFini(api, 0);
 #else
         AB_Banking_OnlineFini(api);
diff --git a/src/import-export/aqbanking/gnc-gwen-gui.c b/src/import-export/aqbanking/gnc-gwen-gui.c
index 5660412344..9bc24549d3 100644
--- a/src/import-export/aqbanking/gnc-gwen-gui.c
+++ b/src/import-export/aqbanking/gnc-gwen-gui.c
@@ -132,6 +132,9 @@ static gint setpasswordstatus_cb(GWEN_GUI *gwen_gui, const gchar *token,
                                  GWEN_GUI_PASSWORD_STATUS status, guint32 guiid);
 static gint loghook_cb(GWEN_GUI *gwen_gui, const gchar *log_domain,
                        GWEN_LOGGER_LEVEL priority, const gchar *text);
+#ifdef AQBANKING_VERSION_5_PLUS
+typedef GWEN_SYNCIO GWEN_IO_LAYER;
+#endif
 static gint checkcert_cb(GWEN_GUI *gwen_gui, const GWEN_SSLCERTDESCR *cert,
                          GWEN_IO_LAYER *io, guint32 guiid);