diff --git a/cmake/FindSamba.cmake b/cmake/FindSamba.cmake
--- a/cmake/FindSamba.cmake
+++ b/cmake/FindSamba.cmake
@@ -36,6 +36,8 @@
    set(CMAKE_REQUIRED_INCLUDES ${CMAKE_REQUIRED_INCLUDES} ${SAMBA_INCLUDE_DIR})
    check_symbol_exists(smbc_set_context "libsmbclient.h" SAMBA_HAVE_SMBC_SET_CONTEXT)
    check_symbol_exists(smbc_option_set "libsmbclient.h" SAMBA_HAVE_SMBC_OPTION_SET)
+   # exists in Samba >= 4.10 (since commit 0dae4e2f5c65)
+   check_symbol_exists(smbc_setOptionProtocols "libsmbclient.h" SAMBA_HAVE_SMBC_SETOPTIONPROTOCOLS)
    cmake_pop_check_state()
    # fail if smbc_set_context() was required but hasn't been found
    if (SAMBA_REQUIRE_SMBC_SET_CONTEXT AND NOT SAMBA_HAVE_SMBC_SET_CONTEXT)
@@ -45,6 +47,9 @@
    if (SAMBA_REQUIRE_SMBC_OPTION_SET AND NOT SAMBA_HAVE_SMBC_OPTION_SET)
       set(SAMBA_FOUND FALSE)
    endif (SAMBA_REQUIRE_SMBC_OPTION_SET AND NOT SAMBA_HAVE_SMBC_OPTION_SET)
+   if (SAMBA_HAVE_SMBC_SETOPTIONPROTOCOLS)
+      add_definitions(-DHAVE_SMBC_SETOPTIONPROTOCOLS)
+   endif (SAMBA_HAVE_SMBC_SETOPTIONPROTOCOLS)
 else(SAMBA_INCLUDE_DIR AND SAMBA_LIBRARIES)
    set(SAMBA_FOUND FALSE)
    set(SAMBA_HAVE_SMBC_SET_CONTEXT FALSE)
diff --git a/smb/kio_smb.h b/smb/kio_smb.h
--- a/smb/kio_smb.h
+++ b/smb/kio_smb.h
@@ -88,7 +88,6 @@
 
 //===========================================================================
 
-
 class SMBSlave : public QObject, public KIO::SlaveBase
 {
     Q_OBJECT
@@ -222,6 +221,10 @@
 
 public:
 
+    mutable int smb_force_protocol = 0;
+    mutable const char* smb_min_proto = NULL;
+    mutable const char* smb_max_proto = NULL;
+
     //-----------------------------------------------------------------------
     // smbclient authentication callback (note that this is called by  the
     // global ::auth_smbc_get_data() call.
diff --git a/smb/kio_smb_auth.cpp b/smb/kio_smb_auth.cpp
--- a/smb/kio_smb_auth.cpp
+++ b/smb/kio_smb_auth.cpp
@@ -190,6 +190,13 @@
 	    return false;
 	}
 
+#ifdef HAVE_SMBC_SETOPTIONPROTOCOLS
+	if (smb_force_protocol && (smb_min_proto || smb_max_proto)) {
+		smbc_setOptionProtocols(smb_context, smb_min_proto, smb_max_proto);
+		qCDebug(KIO_SMB) << "Executed smbc_setOptionProtocols";
+	}
+#endif
+
 #ifdef DEPRECATED_SMBC_INTERFACE // defined by libsmbclient.h of Samba 3.2
 
 	/* New libsmbclient interface of Samba 3.2 */
diff --git a/smb/kio_smb_browse.cpp b/smb/kio_smb_browse.cpp
--- a/smb/kio_smb_browse.cpp
+++ b/smb/kio_smb_browse.cpp
@@ -195,6 +195,17 @@
         }
     }
     if (surl == QLatin1String("smb://")) {
+#ifdef HAVE_SMBC_SETOPTIONPROTOCOLS
+		// Samba 4.8 changed default 'client max protocol' from NT1 to SMB3,
+		// together with fixes of Badlock, it broke browsing smb:// with
+		// default settings, because only NT1 (SMB1) protocol can browse network.
+		// Samba 4.10 made it possible to set min/max protocol version
+		// via libsmbclient API.
+		qCDebug(KIO_SMB) << "Setting client max protocol = NT1 for browsing SMB network";
+		smb_force_protocol = 1;
+		smb_min_proto = "NT1";
+		smb_max_proto = "NT1";
+#endif
         return kurl; //unchanged
     }