diff --git a/gns3server/controller/node.py b/gns3server/controller/node.py
index d42b6e68..796c08aa 100644
--- a/gns3server/controller/node.py
+++ b/gns3server/controller/node.py
@@ -254,7 +254,7 @@ class Node:
         try:
             self._width, self._height, filetype = self._project.controller.symbols.get_size(val)
         except (ValueError, OSError) as e:
-            log.error("Could not write symbol: {}".format(e))
+            log.error("Could not set symbol: {}".format(e))
             # If symbol is invalid we replace it by the default
             self.symbol = ":/symbols/computer.svg"
         if self._label is None:
diff --git a/gns3server/handlers/api/controller/symbol_handler.py b/gns3server/handlers/api/controller/symbol_handler.py
index 3d378766..92e2d12a 100644
--- a/gns3server/handlers/api/controller/symbol_handler.py
+++ b/gns3server/handlers/api/controller/symbol_handler.py
@@ -60,7 +60,7 @@ class SymbolHandler:
         r"/symbols/{symbol_id:.+}/raw",
         description="Write the symbol file",
         status_codes={
-            200: "Symbol returned"
+            200: "Symbol written"
         },
         raw=True)
     def upload(request, response):
@@ -78,6 +78,7 @@ class SymbolHandler:
                     f.write(chunk)
         except (UnicodeEncodeError, OSError) as e:
             raise aiohttp.web.HTTPConflict(text="Could not write symbol file '{}': {}".format(path, e))
+
         # Reset the symbol list
         controller.symbols.list()
         response.set_status(204)
diff --git a/gns3server/utils/picture.py b/gns3server/utils/picture.py
index d7c3103b..3e9fd416 100644
--- a/gns3server/utils/picture.py
+++ b/gns3server/utils/picture.py
@@ -15,6 +15,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import re
 import io
 import struct
 from xml.etree.ElementTree import ElementTree, ParseError
@@ -103,13 +104,21 @@ def get_size(data, default_width=0, default_height=0):
         root = tree.getroot()
 
         try:
-            width_attr = root.attrib.get("width", "0")
-            height_attr = root.attrib.get("height", "0")
+            width_attr = root.attrib.get("width", "100%")
+            height_attr = root.attrib.get("height", "100%")
             if width_attr.endswith("%") or height_attr.endswith("%"):
                 # check to viewBox attribute if width or height value is a percentage
-                _, _, width_attr, height_attr = root.attrib.get("viewBox").split()
+                viewbox = root.attrib.get("viewBox")
+                if not viewbox:
+                    raise ValueError("Invalid SVG file: missing viewBox attribute")
+                _, _, viewbox_width, viewbox_height = re.split(r'[\s,]+', viewbox)
+            if width_attr.endswith("%"):
+                width = _svg_convert_size(viewbox_width, width_attr)
             else:
                 width = _svg_convert_size(width_attr)
+            if height_attr.endswith("%"):
+                height = _svg_convert_size(viewbox_height, height_attr)
+            else:
                 height = _svg_convert_size(height_attr)
         except (AttributeError, IndexError) as e:
             raise ValueError("Invalid SVG file: {}".format(e))
@@ -117,11 +126,12 @@ def get_size(data, default_width=0, default_height=0):
     return width, height, filetype
 
 
-def _svg_convert_size(size):
+def _svg_convert_size(size, percent=None):
     """
     Convert svg size to the px version
 
     :param size: String with the size
+    :param percent: String with the percentage, None = 100%
     """
 
     # https://www.w3.org/TR/SVG/coords.html#Units
@@ -133,8 +143,11 @@ def _svg_convert_size(size):
         "in": 90,
         "px": 1
     }
-    if len(size) > 3:
+    factor = 1.0
+    if len(size) >= 3:
         if size[-2:] in conversion_table:
-            return round(float(size[:-2]) * conversion_table[size[-2:]])
-
-    return round(float(size))
+            factor = conversion_table[size[-2:]]
+            size = size[:-2]
+    if percent:
+        factor *= float(percent.rstrip("%")) / 100.0
+    return round(float(size) * factor)