diff --git a/dlls/wldap32/ber.c b/dlls/wldap32/ber.c
index 482de464234..f7865f94e03 100644
--- a/dlls/wldap32/ber.c
+++ b/dlls/wldap32/ber.c
@@ -51,7 +51,7 @@ BerElement * CDECL ber_alloc_t( int options )
     BerElement *ret;
 
     if (!(ret = malloc( sizeof(*ret) ))) return NULL;
-    if (!(BER(ret) = ldap_funcs->fn_ber_alloc_t( options )))
+    if (ldap_funcs->fn_ber_alloc_t( options, (void **)&BER(ret) ))
     {
         free( ret );
         return NULL;
@@ -226,7 +226,7 @@ BerElement * CDECL ber_init( BERVAL *berval )
         free( ret );
         return NULL;
     }
-    if (!(BER(ret) = ldap_funcs->fn_ber_init( bervalU )))
+    if (ldap_funcs->fn_ber_init( bervalU, (void **)&BER(ret) ))
     {
         free( ret );
         ret = NULL;
diff --git a/dlls/wldap32/dn.c b/dlls/wldap32/dn.c
index 1528d8aef1e..3c9edcdd07e 100644
--- a/dlls/wldap32/dn.c
+++ b/dlls/wldap32/dn.c
@@ -75,7 +75,7 @@ WCHAR * CDECL ldap_dn2ufnW( WCHAR *dn )
 
     if (!(dnU = strWtoU( dn ))) return NULL;
 
-    retU = ldap_funcs->fn_ldap_dn2ufn( dnU );
+    ldap_funcs->fn_ldap_dn2ufn( dnU, &retU );
     ret = strUtoW( retU );
 
     free( dnU );
@@ -131,7 +131,7 @@ WCHAR ** CDECL ldap_explode_dnW( WCHAR *dn, ULONG notypes )
 
     if (!(dnU = strWtoU( dn ))) return NULL;
 
-    retU = ldap_funcs->fn_ldap_explode_dn( dnU, notypes );
+    ldap_funcs->fn_ldap_explode_dn( dnU, notypes, &retU );
     ret = strarrayUtoW( retU );
 
     free( dnU );
@@ -185,7 +185,7 @@ WCHAR * CDECL ldap_get_dnW( LDAP *ld, LDAPMessage *entry )
 
     if (!ld || !entry) return NULL;
 
-    retU = ldap_funcs->fn_ldap_get_dn( CTX(ld), MSG(entry) );
+    ldap_funcs->fn_ldap_get_dn( CTX(ld), MSG(entry), &retU );
 
     ret = strUtoW( retU );
     ldap_funcs->fn_ldap_memfree( retU );
diff --git a/dlls/wldap32/libldap.c b/dlls/wldap32/libldap.c
index 02ba0e01675..8ace7632fad 100644
--- a/dlls/wldap32/libldap.c
+++ b/dlls/wldap32/libldap.c
@@ -59,9 +59,10 @@ C_ASSERT( sizeof(struct timevalU) == sizeof(struct timeval) );
 
 static LDAPMod *nullmods[] = { NULL };
 
-static void * CDECL wrap_ber_alloc_t( int options )
+static int CDECL wrap_ber_alloc_t( int options, void **ret )
 {
-    return ber_alloc_t( options );
+    *ret = ber_alloc_t( options );
+    return *ret ? LDAP_SUCCESS : WLDAP32_LBER_ERROR;
 }
 
 static void CDECL wrap_ber_bvecfree( struct bervalU **berval )
@@ -105,9 +106,10 @@ static void CDECL wrap_ber_free( void *ber, int freebuf )
     ber_free( ber, freebuf );
 }
 
-static void * CDECL wrap_ber_init( struct bervalU *berval )
+static int CDECL wrap_ber_init( struct bervalU *berval, void **ret )
 {
-    return ber_init( (struct berval *)berval );
+    *ret = ber_init( (struct berval *)berval );
+    return *ret ? LDAP_SUCCESS : WLDAP32_LBER_ERROR;
 }
 
 static unsigned int CDECL wrap_ber_next_element( void *ber, unsigned int *ret_len, char *last )
@@ -260,14 +262,16 @@ static int CDECL wrap_ldap_delete_ext_s( void *ld, const char *dn, LDAPControlU
     return ldap_delete_ext_s( ld, dn ? dn : "", (LDAPControl **)serverctrls, (LDAPControl **)clientctrls );
 }
 
-static char * CDECL wrap_ldap_dn2ufn( const char *dn )
+static int CDECL wrap_ldap_dn2ufn( const char *dn, char **ret )
 {
-    return ldap_dn2ufn( dn );
+    *ret = ldap_dn2ufn( dn );
+    return *ret ? 0 : -1;
 }
 
-static char ** CDECL wrap_ldap_explode_dn( const char *dn, int notypes )
+static int CDECL wrap_ldap_explode_dn( const char *dn, int notypes, char ***ret )
 {
-    return ldap_explode_dn( dn, notypes );
+    *ret = ldap_explode_dn( dn, notypes );
+    return *ret ? 0 : -1;
 }
 
 static int CDECL wrap_ldap_extended_operation( void *ld, const char *oid, struct bervalU *data, LDAPControlU **serverctrls,
@@ -285,24 +289,28 @@ static int CDECL wrap_ldap_extended_operation_s( void *ld, const char *oid, stru
                                       (LDAPControl **)clientctrls, retoid, (struct berval **)retdata );
 }
 
-static char * CDECL wrap_ldap_get_dn( void *ld, void *entry )
+static int CDECL wrap_ldap_get_dn( void *ld, void *entry, char **ret )
 {
-    return ldap_get_dn( ld, entry );
+    *ret = ldap_get_dn( ld, entry );
+    return *ret ? 0 : -1;
 }
 
-static char * CDECL wrap_ldap_first_attribute( void *ld, void *entry, void **ber )
+static int CDECL wrap_ldap_first_attribute( void *ld, void *entry, void **ber, char **ret )
 {
-    return ldap_first_attribute( ld, entry, (BerElement **)ber );
+    *ret = ldap_first_attribute( ld, entry, (BerElement **)ber );
+    return *ret ? 0 : -1;
 }
 
-static void * CDECL wrap_ldap_first_entry( void *ld, void *chain )
+static int CDECL wrap_ldap_first_entry( void *ld, void *chain, void **ret )
 {
-    return ldap_first_entry( ld, chain );
+    *ret = ldap_first_entry( ld, chain );
+    return *ret ? 0 : -1;
 }
 
-static void * CDECL wrap_ldap_first_reference( void *ld, void *chain )
+static int CDECL wrap_ldap_first_reference( void *ld, void *chain, void **ret )
 {
-    return ldap_first_reference( ld, chain );
+    *ret = ldap_first_reference( ld, chain );
+    return *ret ? 0 : -1;
 }
 
 static int CDECL wrap_ldap_get_option( void *ld, int option, void *value )
@@ -310,9 +318,10 @@ static int CDECL wrap_ldap_get_option( void *ld, int option, void *value )
     return ldap_get_option( ld, option, value );
 }
 
-static struct bervalU ** CDECL wrap_ldap_get_values_len( void *ld, void *entry, const char *attr )
+static int CDECL wrap_ldap_get_values_len( void *ld, void *entry, const char *attr, struct bervalU ***ret )
 {
-    return (struct bervalU **)ldap_get_values_len( ld, entry, attr );
+    *ret = (struct bervalU **)ldap_get_values_len( ld, entry, attr );
+    return *ret ? 0 : -1;
 }
 
 static int CDECL wrap_ldap_initialize( void **ld, const char *url )
@@ -350,19 +359,22 @@ static int CDECL wrap_ldap_msgfree( void *msg )
     return ldap_msgfree( msg );
 }
 
-static char * CDECL wrap_ldap_next_attribute( void *ld, void *entry, void *ber )
+static int CDECL wrap_ldap_next_attribute( void *ld, void *entry, void *ber, char **ret )
 {
-    return ldap_next_attribute( ld, entry, ber );
+    *ret = ldap_next_attribute( ld, entry, ber );
+    return *ret ? 0 : -1;
 }
 
-static void * CDECL wrap_ldap_next_entry( void *ld, void *entry )
+static int CDECL wrap_ldap_next_entry( void *ld, void *entry, void **ret )
 {
-    return ldap_next_entry( ld, entry );
+    *ret = ldap_next_entry( ld, entry );
+    return *ret ? 0 : -1;
 }
 
-static void * CDECL wrap_ldap_next_reference( void *ld, void *entry )
+static int CDECL wrap_ldap_next_reference( void *ld, void *entry, void **ret )
 {
-    return ldap_next_reference( ld, entry );
+    *ret = ldap_next_reference( ld, entry );
+    return *ret ? 0 : -1;
 }
 
 static int CDECL wrap_ldap_parse_extended_result( void *ld, void *result, char **retoid, struct bervalU **retdata, int free )
diff --git a/dlls/wldap32/libldap.h b/dlls/wldap32/libldap.h
index aec1f13a754..788a6dff5cd 100644
--- a/dlls/wldap32/libldap.h
+++ b/dlls/wldap32/libldap.h
@@ -95,13 +95,13 @@ struct sasl_interactive_bind_id
 
 struct ldap_funcs
 {
-    void * (CDECL *fn_ber_alloc_t)(int);
+    int (CDECL *fn_ber_alloc_t)(int, void **);
     void (CDECL *fn_ber_bvecfree)(struct bervalU **);
     void (CDECL *fn_ber_bvfree)(struct bervalU *);
     unsigned int (CDECL *fn_ber_first_element)(void *, unsigned int *, char **);
     int (CDECL *fn_ber_flatten)(void *, struct bervalU **);
     void (CDECL *fn_ber_free)(void *, int);
-    void * (CDECL *fn_ber_init)(struct bervalU *);
+    int (CDECL *fn_ber_init)(struct bervalU *, void **);
     unsigned int (CDECL *fn_ber_next_element)(void *, unsigned int *, char *);
     unsigned int (CDECL *fn_ber_peek_tag)(void *, unsigned int *);
     unsigned int (CDECL *fn_ber_skip_tag)(void *, unsigned int *);
@@ -124,27 +124,27 @@ struct ldap_funcs
     int (CDECL *fn_ldap_create_vlv_control)(void *, LDAPVLVInfoU *, LDAPControlU **);
     int (CDECL *fn_ldap_delete_ext)(void *, const char *, LDAPControlU **, LDAPControlU **, ULONG *);
     int (CDECL *fn_ldap_delete_ext_s)(void *, const char *, LDAPControlU **, LDAPControlU **);
-    char * (CDECL *fn_ldap_dn2ufn)(const char *);
-    char ** (CDECL *fn_ldap_explode_dn)(const char *, int);
+    int (CDECL *fn_ldap_dn2ufn)(const char *, char **);
+    int (CDECL *fn_ldap_explode_dn)(const char *, int, char ***);
     int (CDECL *fn_ldap_extended_operation)(void *, const char *, struct bervalU *, LDAPControlU **,
                                             LDAPControlU **, ULONG *);
     int (CDECL *fn_ldap_extended_operation_s)(void *, const char *, struct bervalU *, LDAPControlU **,
                                               LDAPControlU **, char **, struct bervalU **);
-    char * (CDECL *fn_ldap_get_dn)(void *, void *);
+    int (CDECL *fn_ldap_get_dn)(void *, void *, char **);
     int (CDECL *fn_ldap_get_option)(void *, int, void *);
-    struct bervalU ** (CDECL *fn_ldap_get_values_len)(void *, void *, const char *);
+    int (CDECL *fn_ldap_get_values_len)(void *, void *, const char *, struct bervalU ***);
     int (CDECL *fn_ldap_initialize)(void **, const char *);
-    char * (CDECL *fn_ldap_first_attribute)(void *, void *, void **);
-    void * (CDECL *fn_ldap_first_entry)(void *, void *);
-    void * (CDECL *fn_ldap_first_reference)(void *, void *);
+    int (CDECL *fn_ldap_first_attribute)(void *, void *, void **, char **);
+    int (CDECL *fn_ldap_first_entry)(void *, void *, void **);
+    int (CDECL *fn_ldap_first_reference)(void *, void *, void **);
     void (CDECL *fn_ldap_memfree)(void *);
     void (CDECL *fn_ldap_memvfree)(void **);
     int (CDECL *fn_ldap_modify_ext)(void *, const char *, LDAPModU **, LDAPControlU **, LDAPControlU **, ULONG *);
     int (CDECL *fn_ldap_modify_ext_s)(void *, const char *, LDAPModU **, LDAPControlU **, LDAPControlU **);
     int (CDECL *fn_ldap_msgfree)(void *);
-    char * (CDECL *fn_ldap_next_attribute)(void *, void *, void *);
-    void * (CDECL *fn_ldap_next_entry)(void *, void *);
-    void * (CDECL *fn_ldap_next_reference)(void *, void *);
+    int (CDECL *fn_ldap_next_attribute)(void *, void *, void *, char **);
+    int (CDECL *fn_ldap_next_entry)(void *, void *, void **);
+    int (CDECL *fn_ldap_next_reference)(void *, void *, void **);
     int (CDECL *fn_ldap_parse_extended_result)(void *, void *, char **, struct bervalU **, int);
     int (CDECL *fn_ldap_parse_reference)(void *, void *, char ***, LDAPControlU ***, int);
     int (CDECL *fn_ldap_parse_result)(void *, void *, int *, char **, char **, char ***, LDAPControlU ***, int);
diff --git a/dlls/wldap32/misc.c b/dlls/wldap32/misc.c
index dbda4609ff2..4810f2884f9 100644
--- a/dlls/wldap32/misc.c
+++ b/dlls/wldap32/misc.c
@@ -299,7 +299,7 @@ WCHAR * CDECL ldap_first_attributeW( LDAP *ld, LDAPMessage *entry, BerElement **
 
     if (!ld || !entry) return NULL;
 
-    retU = ldap_funcs->fn_ldap_first_attribute( CTX(ld), MSG(entry), &berU );
+    ldap_funcs->fn_ldap_first_attribute( CTX(ld), MSG(entry), &berU, &retU );
     if (retU && (ber = malloc( sizeof(*ber) )))
     {
         BER(ber) = (char *)berU;
@@ -335,8 +335,7 @@ LDAPMessage * CDECL ldap_first_entry( LDAP *ld, LDAPMessage *res )
 
     if (!ld || !res) return NULL;
 
-    msgU = ldap_funcs->fn_ldap_first_entry( CTX(ld), MSG(res) );
-    if (msgU)
+    if (!ldap_funcs->fn_ldap_first_entry( CTX(ld), MSG(res), &msgU ))
     {
         assert( msgU == MSG(res) );
         return res;
@@ -366,8 +365,7 @@ LDAPMessage * CDECL ldap_first_reference( LDAP *ld, LDAPMessage *res )
 
     if (!ld) return NULL;
 
-    msgU = ldap_funcs->fn_ldap_first_reference( CTX(ld), MSG(res) );
-    if (msgU)
+    if (!ldap_funcs->fn_ldap_first_reference( CTX(ld), MSG(res), &msgU ))
     {
         assert( msgU == MSG(res) );
         return res;
@@ -479,8 +477,7 @@ WCHAR * CDECL ldap_next_attributeW( LDAP *ld, LDAPMessage *entry, BerElement *pt
 
     if (!ld || !entry || !ptr) return NULL;
 
-    retU = ldap_funcs->fn_ldap_next_attribute( CTX(ld), MSG(entry), BER(ptr) );
-    if (retU)
+    if (!ldap_funcs->fn_ldap_next_attribute( CTX(ld), MSG(entry), BER(ptr), &retU ))
     {
         ret = strUtoW( retU );
         ldap_funcs->fn_ldap_memfree( retU );
@@ -516,7 +513,7 @@ LDAPMessage * CDECL ldap_next_entry( LDAP *ld, LDAPMessage *entry )
 
     if (entry->lm_next) return entry->lm_next;
 
-    msgU = ldap_funcs->fn_ldap_next_entry( CTX(ld), MSG(entry) );
+    ldap_funcs->fn_ldap_next_entry( CTX(ld), MSG(entry), &msgU );
     if (msgU && (msg = calloc( 1, sizeof(*msg) )))
     {
         MSG(msg) = msgU;
@@ -553,7 +550,7 @@ LDAPMessage * CDECL ldap_next_reference( LDAP *ld, LDAPMessage *entry )
 
     if (entry->lm_next) return entry->lm_next;
 
-    msgU = ldap_funcs->fn_ldap_next_reference( CTX(ld), MSG(entry) );
+    ldap_funcs->fn_ldap_next_reference( CTX(ld), MSG(entry), &msgU );
     if (msgU && (msg = calloc( 1, sizeof(*msg) )))
     {
         MSG(msg) = msgU;
diff --git a/dlls/wldap32/option.c b/dlls/wldap32/option.c
index ec3830d4ab3..b3bc4e4d4eb 100644
--- a/dlls/wldap32/option.c
+++ b/dlls/wldap32/option.c
@@ -377,11 +377,10 @@ static BOOL query_supported_server_ctrls( LDAP *ld )
                                                        attrs, FALSE, NULL, NULL, NULL, 0, &res ) );
     if (ret != LDAP_SUCCESS) return FALSE;
 
-    entry = ldap_funcs->fn_ldap_first_entry( CTX(ld), res );
-    if (entry)
+    if (!ldap_funcs->fn_ldap_first_entry( CTX(ld), res, &entry ))
     {
         ULONG count, i;
-        ctrls = ldap_funcs->fn_ldap_get_values_len( CTX(ld), entry, attrs[0] );
+        ldap_funcs->fn_ldap_get_values_len( CTX(ld), entry, attrs[0], &ctrls );
         count = ldap_funcs->fn_ldap_count_values_len( ctrls );
         for (i = 0; i < count; i++) TRACE("%u: %s\n", i, debugstr_an( ctrls[i]->bv_val, ctrls[i]->bv_len ));
         *(struct bervalU ***)&SERVER_CTRLS(ld) = ctrls;
diff --git a/dlls/wldap32/value.c b/dlls/wldap32/value.c
index d7fc1902bde..814bfda00fb 100644
--- a/dlls/wldap32/value.c
+++ b/dlls/wldap32/value.c
@@ -197,7 +197,7 @@ WCHAR ** CDECL ldap_get_valuesW( LDAP *ld, LDAPMessage *entry, WCHAR *attr )
 
     if (!ld || !entry || !attr || !(attrU = strWtoU( attr ))) return NULL;
 
-    if ((bv = ldap_funcs->fn_ldap_get_values_len( CTX(ld), MSG(entry), attrU )))
+    if (!ldap_funcs->fn_ldap_get_values_len( CTX(ld), MSG(entry), attrU, &bv ))
     {
         retU = bv2str_array( bv );
         ret = strarrayUtoW( retU );
@@ -259,7 +259,7 @@ struct berval ** CDECL ldap_get_values_lenW( LDAP *ld, LDAPMessage *message, WCH
 
     if (!ld || !message || !attr || !(attrU = strWtoU( attr ))) return NULL;
 
-    if ((retU = ldap_funcs->fn_ldap_get_values_len( CTX(ld), MSG(message), attrU )))
+    if (!ldap_funcs->fn_ldap_get_values_len( CTX(ld), MSG(message), attrU, &retU ))
     {
         ret = bvarrayUtoW( retU );
         bvarrayfreeU( retU );