diff --git a/gtk/gtkicontheme.c b/gtk/gtkicontheme.c
index e728b0bdb7..1958b7d133 100644
--- a/gtk/gtkicontheme.c
+++ b/gtk/gtkicontheme.c
@@ -4144,7 +4144,7 @@ gtk_icon_info_load_symbolic_svg (GtkIconInfo    *icon_info,
   width = g_strdup_printf ("%d", icon_info->symbolic_width);
   height = g_strdup_printf ("%d", icon_info->symbolic_height);
 
-  escaped_file_data = g_markup_escape_text (file_data, file_len);
+  escaped_file_data = g_base64_encode ((guchar *) file_data, file_len);
   g_free (file_data);
 
   g_ascii_dtostr (alphastr, G_ASCII_DTOSTR_BUF_SIZE, CLAMP (alpha, 0, 1));
@@ -4169,7 +4169,7 @@ gtk_icon_info_load_symbolic_svg (GtkIconInfo    *icon_info,
                       "      fill: ", css_success, " !important;\n"
                       "    }\n"
                       "  </style>\n"
-                      "  <g opacity=\"", alphastr, "\" ><xi:include href=\"data:text/xml,", escaped_file_data, "\"/></g>\n"
+                      "  <g opacity=\"", alphastr, "\" ><xi:include href=\"data:text/xml;base64,", escaped_file_data, "\"/></g>\n"
                       "</svg>",
                       NULL);
   g_free (escaped_file_data);
diff --git a/gtk/tools/gdkpixbufutils.c b/gtk/tools/gdkpixbufutils.c
index b47ebf9df8..0ed23bd3dc 100644
--- a/gtk/tools/gdkpixbufutils.c
+++ b/gtk/tools/gdkpixbufutils.c
@@ -178,7 +178,7 @@ load_symbolic_svg (const char     *file_data,
   svg_height = g_strdup_printf ("%d", gdk_pixbuf_get_height (pixbuf));
   g_object_unref (pixbuf);
 
-  escaped_file_data = g_markup_escape_text (file_data, file_len);
+  escaped_file_data = g_base64_encode ((guchar *) file_data, file_len);
 
   data = g_strconcat ("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?>\n"
                       "<svg version=\"1.1\"\n"
@@ -200,7 +200,7 @@ load_symbolic_svg (const char     *file_data,
                       "      fill: ", css_success, " !important;\n"
                       "    }\n"
                       "  </style>\n"
-                      "  <xi:include href=\"data:text/xml,", escaped_file_data, "\"/>\n"
+                      "  <xi:include href=\"data:text/xml;base64,", escaped_file_data, "\"/>\n"
                       "</svg>",
                       NULL);
   g_free (escaped_file_data);