diff --git a/CHANGELOG.md b/CHANGELOG.md
index a506f93b..8c2ee5fc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -73,6 +73,7 @@
 
 * [#634](https://github.com/foosel/OctoPrint/pull/634) - Fixed missing `branch` fields in version dicts generated
   by versioneer
+* [IRC] Don't hiccup on slic3r filament_diameter comments generated for multi extruder setups
 
 ## 1.1.1 (2014-10-27)
 
diff --git a/src/octoprint/util/gcodeInterpreter.py b/src/octoprint/util/gcodeInterpreter.py
index c886999a..79ba279f 100644
--- a/src/octoprint/util/gcodeInterpreter.py
+++ b/src/octoprint/util/gcodeInterpreter.py
@@ -73,7 +73,14 @@ class gcode(object):
 			if ';' in line:
 				comment = line[line.find(';')+1:].strip()
 				if comment.startswith("filament_diameter"):
-					self._filamentDiameter = float(comment.split("=", 1)[1].strip())
+					filamentValue = comment.split("=", 1)[1].strip()
+					try:
+						self._filamentDiameter = float(filamentValue)
+					except ValueError:
+						try:
+							self._filamentDiameter = float(filamentValue.split(",")[0].strip())
+						except ValueError:
+							self._filamentDiameter = 0.0
 				elif comment.startswith("CURA_PROFILE_STRING"):
 					curaOptions = self._parseCuraProfileString(comment)
 					if "filament_diameter" in curaOptions: