diff --git a/test/php/library/Icingadb/Util/PerfdataTest.php b/test/php/library/Icingadb/Util/PerfdataTest.php
index e31c86d00..d3e63d14f 100644
--- a/test/php/library/Icingadb/Util/PerfdataTest.php
+++ b/test/php/library/Icingadb/Util/PerfdataTest.php
@@ -259,6 +259,17 @@ public function testWhetherGetMinimumValueReturnsCorrectValues()
             Perfdata::fromString('test=1;;;1337.5')->getMinimumValue(),
             'Perfdata::getMinimumValue does not return correct values'
         );
+
+        $this->assertSame(
+            '10,00',
+            Perfdata::fromString('test=1;;;;10,00')->getMinimumValue(),
+            'Perfdata::getMinimumValue does not return correct values'
+        );
+        $this->assertSame(
+            'foo',
+            Perfdata::fromString('test=1;;;;foo')->getMinimumValue(),
+            'Perfdata::getMinimumValue does not return correct values'
+        );
     }
 
     /**
@@ -276,6 +287,16 @@ public function testWhetherGetMaximumValueReturnsCorrectValues()
             Perfdata::fromString('test=1;;;;1337.5')->getMaximumValue(),
             'Perfdata::getMaximumValue does not return correct values'
         );
+        $this->assertSame(
+            '10,00',
+            Perfdata::fromString('test=1;;;;10,00')->getMaximumValue(),
+            'Perfdata::getMaximumValue does not return correct values'
+        );
+        $this->assertSame(
+            'foo',
+            Perfdata::fromString('test=1;;;;foo')->getMaximumValue(),
+            'Perfdata::getMaximumValue does not return correct values'
+        );
     }
 
     /**
@@ -399,4 +420,16 @@ public function testWhetherPercentagesAreHandledCorrectly()
             'Perfdata objects do not ignore impossible min/max combinations when returning percentages'
         );
     }
+
+    /**
+     * @depends testWhetherFromStringParsesAGivenStringCorrectly
+     */
+    public function testInvalidPerfDataHandling()
+    {
+        $this->assertFalse(Perfdata::fromString('test=1;;;2,00;10,00'));
+        $this->assertFalse(Perfdata::fromString('test=1;;;foo;1000'));
+        $this->assertFalse(Perfdata::fromString('test=1;10@:'));
+        $this->assertFalse(Perfdata::fromString('test=1;foo:'));
+        $this->assertFalse(Perfdata::fromString('test=1;2,2:4,4'));
+    }
 }
diff --git a/test/php/library/Icingadb/Util/ThresholdRangeTest.php b/test/php/library/Icingadb/Util/ThresholdRangeTest.php
index c0d757371..b191e8804 100644
--- a/test/php/library/Icingadb/Util/ThresholdRangeTest.php
+++ b/test/php/library/Icingadb/Util/ThresholdRangeTest.php
@@ -319,5 +319,25 @@ public function testInvalidThresholdNotationsAreRenderedAsIs()
             'foo',
             (string) ThresholdRange::fromString('foo')
         );
+        $this->assertSame(
+            '4,4:2,2',
+            (string) ThresholdRange::fromString('4,4:2,2')
+        );
+    }
+
+    public function testInvalidThresholdNotationsConsideredInValid()
+    {
+        $this->assertFalse(
+            ThresholdRange::fromString('10@')->isValid(),
+            'Invalid threshold notation 10@ considered as valid'
+        );
+        $this->assertFalse(
+            ThresholdRange::fromString('foo')->isValid(),
+            'Invalid threshold notation foo considered as valid'
+        );
+        $this->assertFalse(
+            ThresholdRange::fromString('4,4:2,2')->isValid(),
+            'Invalid threshold notation 4,4:2,2 considered as valid'
+        );
     }
 }