diff --git a/src/octoprint/util/comm.py b/src/octoprint/util/comm.py
index aa71a9ac..0cbaf9fe 100644
--- a/src/octoprint/util/comm.py
+++ b/src/octoprint/util/comm.py
@@ -89,7 +89,7 @@ Groups will be as follows:
   * ``size``: size of the file in bytes (int)
 """
 
-regex_temp = re.compile("(?P<tool>B|T(?P<toolnum>\d*)):\s*(?P<actual>%s)(\s*\/?\s*(?P<target>%s))?" % (regex_positive_float_pattern, regex_positive_float_pattern))
+regex_temp = re.compile("(?P<tool>B|T(?P<toolnum>\d*)):\s*(?P<actual>%s)(\s*\/?\s*(?P<target>%s))?" % (regex_float_pattern, regex_float_pattern))
 """Regex matching temperature entries in line.
 
 Groups will be as follows:
@@ -100,7 +100,7 @@ Groups will be as follows:
   * ``target``: target temperature, if provided (float)
 """
 
-regex_repetierTempExtr = re.compile("TargetExtr(?P<toolnum>\d+):(?P<target>%s)" % regex_positive_float_pattern)
+regex_repetierTempExtr = re.compile("TargetExtr(?P<toolnum>\d+):(?P<target>%s)" % regex_float_pattern)
 """Regex for matching target temp reporting from Repetier.
 
 Groups will be as follows:
@@ -110,7 +110,7 @@ Groups will be as follows:
   * ``target``: new target temperature (float)
 """
 
-regex_repetierTempBed = re.compile("TargetBed:(?P<target>%s)" % regex_positive_float_pattern)
+regex_repetierTempBed = re.compile("TargetBed:(?P<target>%s)" % regex_float_pattern)
 """Regex for matching target temp reporting from Repetier for beds.
 
 Groups will be as follows:
diff --git a/tests/util/test_comm_helpers.py b/tests/util/test_comm_helpers.py
index 5ac6998e..0da2cf60 100644
--- a/tests/util/test_comm_helpers.py
+++ b/tests/util/test_comm_helpers.py
@@ -221,7 +221,9 @@ class TestCommHelpers(unittest.TestCase):
 		("T:23.0 B:60.0", 1, dict(T1=(23.0, None), B=(60.0, None)), 1),
 		("T:23.0/220.0 B:60.0/70.0", 0, dict(T0=(23.0, 220.0), B=(60.0, 70.0)), 0),
 		("ok T:23.0/220.0 T0:23.0/220.0 T1:50.2/210.0 T2:39.4/220.0 B:60.0", 0, dict(T0=(23.0, 220.0), T1=(50.2, 210.0), T2=(39.4, 220.0), B=(60.0, None)), 2),
-		("ok T:50.2/210.0 T0:23.0/220.0 T1:50.2/210.0 T2:39.4/220.0 B:60.0", 1, dict(T0=(23.0, 220.0), T1=(50.2, 210.0), T2=(39.4, 220.0), B=(60.0, None)), 2)
+		("ok T:50.2/210.0 T0:23.0/220.0 T1:50.2/210.0 T2:39.4/220.0 B:60.0", 1, dict(T0=(23.0, 220.0), T1=(50.2, 210.0), T2=(39.4, 220.0), B=(60.0, None)), 2),
+		("ok T:-55.7/0 T0:-55.7/0 T1:150.0/210.0", 0, dict(T0=(-55.7, 0), T1=(150.0, 210.0)), 1),
+		("ok T:150.0/210.0 T0:-55.7/0 T1:150.0/210.0", 1, dict(T0=(-55.7, 0), T1=(150.0, 210.0)), 1)
 	)
 	@unpack
 	def test_process_temperature_line(self, line, current, expected_result, expected_max):