--- a/configure.ac
+++ b/configure.ac
@@ -29,7 +29,7 @@ LT_PREREQ([2.2])
 LT_INIT
 
 # Package dependencies
-GLIB_REQUIRED=2.56.0
+GLIB_REQUIRED=2.54.0
 LIBGTOP_REQUIRED=2.37.2
 GIOMM_REQUIRED=2.26.0
 GLIBMM_REQUIRED=2.22
--- a/src/load-graph.cpp
+++ b/src/load-graph.cpp
@@ -136,7 +136,11 @@ static void draw_background(LoadGraph *g
         if (graph->type == LOAD_GRAPH_NET) {
             // operation orders matters so it's 0 if i == num_bars
             guint64 rate = graph->net.max - (i * graph->net.max / num_bars);
+#if GLIB_CHECK_VERSION(2, 56, 0)
             caption = g_format_size_full (network_in_bits ? rate*8 : rate, network_in_bits ? G_FORMAT_SIZE_BITS : G_FORMAT_SIZE_DEFAULT);
+#else
+            caption = g_format_size (rate);
+#endif
             pango_layout_set_text (layout, caption, -1);
             pango_layout_get_extents (layout, NULL, &extents);
             cairo_move_to (cr, graph->indent - 1.0 * extents.width / PANGO_SCALE + 20, y - 1.0 * extents.height / PANGO_SCALE / 2);
@@ -588,18 +592,34 @@ get_net (LoadGraph *graph)
     bool network_in_bits = ProcData::get_instance()->config.network_in_bits;
     g_autofree gchar *str=NULL, *formatted_str=NULL;
 
+#if GLIB_CHECK_VERSION(2, 56, 0)
     str = g_format_size_full (network_in_bits ? din*8 : din, network_in_bits ? G_FORMAT_SIZE_BITS : G_FORMAT_SIZE_DEFAULT);
+#else
+    str = g_format_size (din);
+#endif
     formatted_str = g_strdup_printf(_("%s/s"), str);
     gtk_label_set_text (GTK_LABEL (graph->labels.net_in), formatted_str);
 
+#if GLIB_CHECK_VERSION(2, 56, 0)
     str = g_format_size_full (network_in_bits ? in*8 : in, network_in_bits ? G_FORMAT_SIZE_BITS : G_FORMAT_SIZE_DEFAULT);
+#else
+    str = g_format_size (in);
+#endif
     gtk_label_set_text (GTK_LABEL (graph->labels.net_in_total), str);
 
+#if GLIB_CHECK_VERSION(2, 56, 0)
     str = g_format_size_full (network_in_bits ? dout*8 : dout, network_in_bits ? G_FORMAT_SIZE_BITS : G_FORMAT_SIZE_DEFAULT);
+#else
+    str = g_format_size (dout);
+#endif
     formatted_str = g_strdup_printf(_("%s/s"), str);
     gtk_label_set_text (GTK_LABEL (graph->labels.net_out), formatted_str);
 
+#if GLIB_CHECK_VERSION(2, 56, 0)
     str = g_format_size_full (network_in_bits ? out*8 : out, network_in_bits ? G_FORMAT_SIZE_BITS : G_FORMAT_SIZE_DEFAULT);
+#else
+    str = g_format_size (out);
+#endif
     gtk_label_set_text (GTK_LABEL (graph->labels.net_out_total), str);
 }
 
--- a/src/procdialogs.cpp
+++ b/src/procdialogs.cpp
@@ -283,6 +283,7 @@ solaris_mode_toggled(GtkToggleButton *bu
 }
 
 
+#if GLIB_CHECK_VERSION(2, 56, 0)
 static void
 network_in_bits_toggled(GtkToggleButton *button, gpointer data)
 {
@@ -292,6 +293,7 @@ network_in_bits_toggled(GtkToggleButton
     toggled = gtk_toggle_button_get_active(button);
     g_settings_set_boolean(settings, procman::settings::network_in_bits.c_str(), toggled);
 }
+#endif
 
 
 
@@ -709,6 +711,7 @@ procdialog_create_preferences_dialog (Pr
     gtk_label_set_mnemonic_widget (GTK_LABEL (label), spin_button);
 
 
+#if GLIB_CHECK_VERSION(2, 56, 0)
     GtkWidget *bits_button;
     bits_button = gtk_check_button_new_with_mnemonic(_("Show network speed in bits"));
     gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(bits_button),
@@ -718,6 +721,7 @@ procdialog_create_preferences_dialog (Pr
     g_signal_connect(G_OBJECT(bits_button), "toggled",
                      G_CALLBACK(network_in_bits_toggled), procdata);
     gtk_box_pack_start(GTK_BOX(vbox2), bits_button, TRUE, TRUE, 0);
+#endif
 
 
 
--- a/src/procman.cpp
+++ b/src/procman.cpp
@@ -106,6 +106,7 @@ solaris_mode_changed_cb(GSettings *setti
 }
 
 
+#if GLIB_CHECK_VERSION(2, 56, 0)
 static void
 network_in_bits_changed_cb(GSettings *settings, const gchar *key, gpointer data)
 {
@@ -114,6 +115,7 @@ network_in_bits_changed_cb(GSettings *se
     procdata->config.network_in_bits = g_settings_get_boolean(settings, key);
     procdata->net_graph->clear_background();
 }
+#endif
 
 
 
@@ -263,9 +265,13 @@ procman_data_new (GSettings *settings)
     std::string detail_string("changed::" + procman::settings::solaris_mode);
     g_signal_connect(G_OBJECT(settings), detail_string.c_str(), G_CALLBACK(solaris_mode_changed_cb), pd);
 
+#if GLIB_CHECK_VERSION(2, 56, 0)
     pd->config.network_in_bits = g_settings_get_boolean(settings, procman::settings::network_in_bits.c_str());
     detail_string = "changed::" + procman::settings::network_in_bits;
     g_signal_connect(G_OBJECT(settings), detail_string.c_str(), G_CALLBACK(network_in_bits_changed_cb), pd);
+#else
+    pd->config.network_in_bits = FALSE;
+#endif
 
     pd->config.show_kill_warning = g_settings_get_boolean (settings, "kill-dialog");
     g_signal_connect (G_OBJECT(settings), "changed::kill-dialog", G_CALLBACK(warning_changed_cb), pd);