diff --git a/src/business/business-core/test/test-customer.c b/src/business/business-core/test/test-customer.c
index 781a838d81..e7e57d3caa 100644
--- a/src/business/business-core/test/test-customer.c
+++ b/src/business/business-core/test/test-customer.c
@@ -38,17 +38,17 @@ static int count = 0;
 static void
 test_string_fcn (QofBook *book, const char *message,
 		 void (*set) (GncCustomer *, const char *str),
-		 const char * (*get)(GncCustomer *));
+		 const char * (*get)(const GncCustomer *));
 
 static void
 test_numeric_fcn (QofBook *book, const char *message,
 		  void (*set) (GncCustomer *, gnc_numeric),
-		  gnc_numeric (*get)(GncCustomer *));
+		  gnc_numeric (*get)(const GncCustomer *));
 
 static void
 test_bool_fcn (QofBook *book, const char *message,
 		  void (*set) (GncCustomer *, gboolean),
-		  gboolean (*get) (GncCustomer *));
+		  gboolean (*get) (const GncCustomer *));
 
 static void
 test_customer (void)
@@ -149,7 +149,7 @@ test_customer (void)
 static void
 test_string_fcn (QofBook *book, const char *message,
 		 void (*set) (GncCustomer *, const char *str),
-		 const char * (*get)(GncCustomer *))
+		 const char * (*get)(const GncCustomer *))
 {
   GncCustomer *customer = gncCustomerCreate (book);
   char const *str = get_random_string ();
@@ -168,7 +168,7 @@ test_string_fcn (QofBook *book, const char *message,
 static void
 test_numeric_fcn (QofBook *book, const char *message,
 		  void (*set) (GncCustomer *, gnc_numeric),
-		  gnc_numeric (*get)(GncCustomer *))
+		  gnc_numeric (*get)(const GncCustomer *))
 {
   GncCustomer *customer = gncCustomerCreate (book);
   gnc_numeric num = gnc_numeric_create (17, 1);
@@ -187,7 +187,7 @@ test_numeric_fcn (QofBook *book, const char *message,
 static void
 test_bool_fcn (QofBook *book, const char *message,
 	       void (*set) (GncCustomer *, gboolean),
-	       gboolean (*get) (GncCustomer *))
+	       gboolean (*get) (const GncCustomer *))
 {
   GncCustomer *customer = gncCustomerCreate (book);
   gboolean num = get_random_boolean ();
diff --git a/src/business/business-core/test/test-employee.c b/src/business/business-core/test/test-employee.c
index 4a201ce792..2d0ec67da7 100644
--- a/src/business/business-core/test/test-employee.c
+++ b/src/business/business-core/test/test-employee.c
@@ -38,17 +38,17 @@ static int count = 0;
 static void
 test_string_fcn (QofBook *book, const char *message,
 		 void (*set) (GncEmployee *, const char *str),
-		 const char * (*get)(GncEmployee *));
+		 const char * (*get)(const GncEmployee *));
 
 static void
 test_numeric_fcn (QofBook *book, const char *message,
 		  void (*set) (GncEmployee *, gnc_numeric),
-		  gnc_numeric (*get)(GncEmployee *));
+		  gnc_numeric (*get)(const GncEmployee *));
 
 static void
 test_bool_fcn (QofBook *book, const char *message,
 		  void (*set) (GncEmployee *, gboolean),
-		  gboolean (*get) (GncEmployee *));
+		  gboolean (*get) (const GncEmployee *));
 
 #if 0
 static void
@@ -138,7 +138,7 @@ test_employee (void)
 static void
 test_string_fcn (QofBook *book, const char *message,
 		 void (*set) (GncEmployee *, const char *str),
-		 const char * (*get)(GncEmployee *))
+		 const char * (*get)(const GncEmployee *))
 {
   GncEmployee *employee = gncEmployeeCreate (book);
   char const *str = get_random_string ();
@@ -157,7 +157,7 @@ test_string_fcn (QofBook *book, const char *message,
 static void
 test_numeric_fcn (QofBook *book, const char *message,
 		  void (*set) (GncEmployee *, gnc_numeric),
-		  gnc_numeric (*get)(GncEmployee *))
+		  gnc_numeric (*get)(const GncEmployee *))
 {
   GncEmployee *employee = gncEmployeeCreate (book);
   gnc_numeric num = gnc_numeric_create (17, 1);
@@ -176,7 +176,7 @@ test_numeric_fcn (QofBook *book, const char *message,
 static void
 test_bool_fcn (QofBook *book, const char *message,
 	       void (*set) (GncEmployee *, gboolean),
-	       gboolean (*get) (GncEmployee *))
+	       gboolean (*get) (const GncEmployee *))
 {
   GncEmployee *employee = gncEmployeeCreate (book);
   gboolean num = get_random_boolean ();
diff --git a/src/business/business-core/test/test-job.c b/src/business/business-core/test/test-job.c
index 3c9bf33b12..8401ae0be0 100644
--- a/src/business/business-core/test/test-job.c
+++ b/src/business/business-core/test/test-job.c
@@ -38,25 +38,25 @@ static int count = 0;
 static void
 test_string_fcn (QofBook *book, const char *message,
 		 void (*set) (GncJob *, const char *str),
-		 const char * (*get)(GncJob *));
+		 const char * (*get)(const GncJob *));
 
 #if 0
 static void
 test_numeric_fcn (QofBook *book, const char *message,
 		  void (*set) (GncJob *, gnc_numeric),
-		  gnc_numeric (*get)(GncJob *));
+		  gnc_numeric (*get)(const GncJob *));
 #endif
 
 static void
 test_bool_fcn (QofBook *book, const char *message,
 		  void (*set) (GncJob *, gboolean),
-		  gboolean (*get) (GncJob *));
+		  gboolean (*get) (const GncJob *));
 
 #if 0
 static void
 test_gint_fcn (QofBook *book, const char *message,
 	       void (*set) (GncJob *, gint),
-	       gint (*get) (GncJob *));
+	       gint (*get) (const GncJob *));
 #endif
 
 static void
@@ -157,7 +157,7 @@ test_job (void)
 static void
 test_string_fcn (QofBook *book, const char *message,
 		 void (*set) (GncJob *, const char *str),
-		 const char * (*get)(GncJob *))
+		 const char * (*get)(const GncJob *))
 {
   GncJob *job = gncJobCreate (book);
   char const *str = get_random_string ();
@@ -176,7 +176,7 @@ test_string_fcn (QofBook *book, const char *message,
 static void
 test_numeric_fcn (QofBook *book, const char *message,
 		  void (*set) (GncJob *, gnc_numeric),
-		  gnc_numeric (*get)(GncJob *))
+		  gnc_numeric (*get)(const GncJob *))
 {
   GncJob *job = gncJobCreate (book);
   gnc_numeric num = gnc_numeric_create (17, 1);
@@ -195,7 +195,7 @@ test_numeric_fcn (QofBook *book, const char *message,
 static void
 test_bool_fcn (QofBook *book, const char *message,
 	       void (*set) (GncJob *, gboolean),
-	       gboolean (*get) (GncJob *))
+	       gboolean (*get) (const GncJob *))
 {
   GncJob *job = gncJobCreate (book);
   gboolean num = get_random_boolean ();
@@ -216,7 +216,7 @@ test_bool_fcn (QofBook *book, const char *message,
 static void
 test_gint_fcn (QofBook *book, const char *message,
 	       void (*set) (GncJob *, gint),
-	       gint (*get) (GncJob *))
+	       gint (*get) (const GncJob *))
 {
   GncJob *job = gncJobCreate (book);
   gint num = 17;
diff --git a/src/business/business-core/test/test-vendor.c b/src/business/business-core/test/test-vendor.c
index 780ccb5fda..7aede94d82 100644
--- a/src/business/business-core/test/test-vendor.c
+++ b/src/business/business-core/test/test-vendor.c
@@ -37,25 +37,25 @@ static int count = 0;
 static void
 test_string_fcn (QofBook *book, const char *message,
 		 void (*set) (GncVendor *, const char *str),
-		 const char * (*get)(GncVendor *));
+		 const char * (*get)(const GncVendor *));
 
 #if 0
 static void
 test_numeric_fcn (QofBook *book, const char *message,
 		  void (*set) (GncVendor *, gnc_numeric),
-		  gnc_numeric (*get)(GncVendor *));
+		  gnc_numeric (*get)(const GncVendor *));
 #endif
 
 static void
 test_bool_fcn (QofBook *book, const char *message,
 		  void (*set) (GncVendor *, gboolean),
-		  gboolean (*get) (GncVendor *));
+		  gboolean (*get) (const GncVendor *));
 
 #if 0
 static void
 test_gint_fcn (QofBook *book, const char *message,
 	       void (*set) (GncVendor *, gint),
-	       gint (*get) (GncVendor *));
+	       gint (*get) (const GncVendor *));
 #endif
 
 static void
@@ -138,7 +138,7 @@ test_vendor (void)
 static void
 test_string_fcn (QofBook *book, const char *message,
 		 void (*set) (GncVendor *, const char *str),
-		 const char * (*get)(GncVendor *))
+		 const char * (*get)(const GncVendor *))
 {
   GncVendor *vendor = gncVendorCreate (book);
   char const *str = get_random_string ();
@@ -157,7 +157,7 @@ test_string_fcn (QofBook *book, const char *message,
 static void
 test_numeric_fcn (QofBook *book, const char *message,
 		  void (*set) (GncVendor *, gnc_numeric),
-		  gnc_numeric (*get)(GncVendor *))
+		  gnc_numeric (*get)(const GncVendor *))
 {
   GncVendor *vendor = gncVendorCreate (book);
   gnc_numeric num = gnc_numeric_create (17, 1);
@@ -176,7 +176,7 @@ test_numeric_fcn (QofBook *book, const char *message,
 static void
 test_bool_fcn (QofBook *book, const char *message,
 	       void (*set) (GncVendor *, gboolean),
-	       gboolean (*get) (GncVendor *))
+	       gboolean (*get) (const GncVendor *))
 {
   GncVendor *vendor = gncVendorCreate (book);
   gboolean num = get_random_boolean ();
@@ -197,7 +197,7 @@ test_bool_fcn (QofBook *book, const char *message,
 static void
 test_gint_fcn (QofBook *book, const char *message,
 	       void (*set) (GncVendor *, gint),
-	       gint (*get) (GncVendor *))
+	       gint (*get) (const GncVendor *))
 {
   GncVendor *vendor = gncVendorCreate (book);
   gint num = 17;