diff --git a/omega-pac/src/conditions.coffee b/omega-pac/src/conditions.coffee
index 144c1a2..44ceab8 100644
--- a/omega-pac/src/conditions.coffee
+++ b/omega-pac/src/conditions.coffee
@@ -524,7 +524,10 @@ module.exports = exports =
       fromStr: (str, condition) ->
         [ip, prefixLength] = str.split('/')
         condition.ip = ip
-        condition.prefixLength = parseInt(prefixLength)
+        addr = @parseIp ip
+        condition.ip = '0.0.0.0' unless addr?
+        condition.prefixLength = parseInt(prefixLength, 10)
+        condition.prefixLength = 0 unless condition.prefixLength >= 0
         condition
 
     'HostLevelsCondition':
@@ -555,8 +558,10 @@ module.exports = exports =
       str: (condition) -> condition.minValue + '~' + condition.maxValue
       fromStr: (str, condition) ->
         [minValue, maxValue] = str.split('~')
-        condition.minValue = minValue
-        condition.maxValue = maxValue
+        condition.minValue = parseInt(minValue, 10)
+        condition.maxValue = parseInt(maxValue, 10)
+        condition.minValue = 1 unless condition.minValue > 0
+        condition.maxValue = 1 unless condition.maxValue > 0
         condition
 
     'WeekdayCondition':
@@ -580,8 +585,10 @@ module.exports = exports =
       str: (condition) -> condition.startDay + '~' + condition.endDay
       fromStr: (str, condition) ->
         [startDay, endDay] = str.split('~')
-        condition.startDay = startDay
-        condition.endDay = endDay
+        condition.startDay = parseInt(startDay, 10)
+        condition.endDay = parseInt(endDay, 10)
+        condition.startDay = 0 unless 0 <= condition.startDay <= 6
+        condition.endDay = 0 unless 0 <= condition.endDay <= 6
         condition
     'TimeCondition':
       abbrs: ['T', 'Time', 'Hour']
@@ -604,7 +611,9 @@ module.exports = exports =
       str: (condition) -> condition.startHour + '~' + condition.endHour
       fromStr: (str, condition) ->
         [startHour, endHour] = str.split('~')
-        condition.startHour = startHour
-        condition.endHour = endHour
+        condition.startHour = parseInt(startHour, 10)
+        condition.endHour = parseInt(endHour, 10)
+        condition.startHour = 0 unless 0 <= condition.startHour < 24
+        condition.endHour = 0 unless 0 <= condition.endHour < 24
         condition
     # coffeelint: enable=missing_fat_arrows
diff --git a/omega-pac/test/conditions.coffee b/omega-pac/test/conditions.coffee
index bec1ff2..11da554 100644
--- a/omega-pac/test/conditions.coffee
+++ b/omega-pac/test/conditions.coffee
@@ -383,7 +383,98 @@ describe 'Conditions', ->
       result = Conditions.str(condition)
       result.should.equal('Ip: 127.0.0.1/16')
       cond = Conditions.fromStr(result)
+      console.log typeof cond.prefixLength
       cond.should.eql(condition)
+    it 'should provide sensible fallbacks for invalid IpCondition', ->
+      cond = Conditions.fromStr('Ip: foo/-233')
+      cond.should.eql(
+        conditionType: 'IpCondition'
+        ip: '0.0.0.0'
+        prefixLength: 0
+      )
+
+      cond = Conditions.fromStr('Ip: nonsense stuff')
+      cond.should.eql(
+        conditionType: 'IpCondition'
+        ip: '0.0.0.0'
+        prefixLength: 0
+      )
+    it 'should provide sensible fallbacks for invalid IpCondition', ->
+      cond = Conditions.fromStr('Ip: 0.0.0.0/-233')
+      cond.should.eql(
+        conditionType: 'IpCondition'
+        ip: '0.0.0.0'
+        prefixLength: 0
+      )
+    it 'should encode & decode HostLevelsCondition correctly', ->
+      condition =
+        conditionType: 'HostLevelsCondition'
+        minValue: 4
+        maxValue: 7
+      result = Conditions.str(condition)
+      result.should.equal('HostLevels: 4~7')
+      cond = Conditions.fromStr(result)
+      cond.should.eql(condition)
+    it 'should provide sensible fallbacks for HostLevels out of range', ->
+      cond = Conditions.fromStr('HostLevels: A~-1')
+      cond.should.eql(
+        conditionType: 'HostLevelsCondition'
+        minValue: 1
+        maxValue: 1
+      )
+
+      cond = Conditions.fromStr('HostLevels: nonsense')
+      cond.should.eql(
+        conditionType: 'HostLevelsCondition'
+        minValue: 1
+        maxValue: 1
+      )
+    it 'should encode & decode WeekdayCondition correctly', ->
+      condition =
+        conditionType: 'WeekdayCondition'
+        startDay: 3
+        endDay: 6
+      result = Conditions.str(condition)
+      result.should.equal('Weekday: 3~6')
+      cond = Conditions.fromStr(result)
+      cond.should.eql(condition)
+    it 'should provide sensible fallbacks for Weekday out of range', ->
+      cond = Conditions.fromStr('Weekday: -1~100')
+      cond.should.eql(
+        conditionType: 'WeekdayCondition'
+        startDay: 0
+        endDay: 0
+      )
+
+      cond = Conditions.fromStr('Weekday: nonsense')
+      cond.should.eql(
+        conditionType: 'WeekdayCondition'
+        startDay: 0
+        endDay: 0
+      )
+    it 'should encode & decode TimeCondition correctly', ->
+      condition =
+        conditionType: 'TimeCondition'
+        startHour: 7
+        endHour: 23
+      result = Conditions.str(condition)
+      result.should.equal('Hour: 7~23')
+      cond = Conditions.fromStr(result)
+      cond.should.eql(condition)
+    it 'should provide sensible fallbacks for Hour out of range', ->
+      cond = Conditions.fromStr('Hour: -1~100')
+      cond.should.eql(
+        conditionType: 'TimeCondition'
+        startHour: 0
+        endHour: 0
+      )
+
+      cond = Conditions.fromStr('Hour: nonsense')
+      cond.should.eql(
+        conditionType: 'TimeCondition'
+        startHour: 0
+        endHour: 0
+      )
     it 'should parse conditions with extra spaces correctly', ->
       Conditions.fromStr('url:    *abcde*   ').should.eql({
         conditionType: 'UrlWildcardCondition'