diff --git a/doc/31-Changelog.md b/doc/31-Changelog.md
index 8a54a47..4ddec69 100644
--- a/doc/31-Changelog.md
+++ b/doc/31-Changelog.md
@@ -14,8 +14,10 @@ Released closed milestones can be found on [GitHub](https://github.com/Icinga/ic
 ## 1.5.1 (pending)
 
 [Issue and PRs](https://github.com/Icinga/icinga-powershell-framework/milestone/17?closed=1)
+
 ### Bugfixes
 
+* [#276](https://github.com/Icinga/icinga-powershell-framework/pull/276) Fixes check value conversion to decimal, which sometimes did not resolve values properly and caused conversion issues
 * [#282](https://github.com/Icinga/icinga-powershell-framework/issues/282) Fixes issue on `System.Text.StringBuilder` which fails to initialize properly on some older Windows systems
 
 ## 1.5.0 (2021-06-02)
diff --git a/lib/core/tools/Test-IcingaDecimal.psm1 b/lib/core/tools/Test-IcingaDecimal.psm1
new file mode 100644
index 0000000..c264fa0
--- /dev/null
+++ b/lib/core/tools/Test-IcingaDecimal.psm1
@@ -0,0 +1,26 @@
+function Test-IcingaDecimal()
+{
+    param (
+        $Value = $null
+    );
+
+    [hashtable]$RetValue = @{
+        'Value'   = $Value;
+        'Decimal' = $FALSE;
+    };
+
+    if ($null -eq $Value -Or [string]::IsNullOrEmpty($Value)) {
+        return $RetValue;
+    }
+
+    $TmpValue = ([string]$Value).Replace(',', '.');
+
+    if ((Test-Numeric $TmpValue) -eq $FALSE) {
+        return $RetValue;
+    }
+
+    $RetValue.Value   = [decimal]$TmpValue;
+    $RetValue.Decimal = $TRUE;
+
+    return $RetValue;
+}
diff --git a/lib/icinga/plugin/Compare-IcingaPluginThresholds.psm1 b/lib/icinga/plugin/Compare-IcingaPluginThresholds.psm1
index c169675..d384711 100644
--- a/lib/icinga/plugin/Compare-IcingaPluginThresholds.psm1
+++ b/lib/icinga/plugin/Compare-IcingaPluginThresholds.psm1
@@ -18,6 +18,17 @@ function Compare-IcingaPluginThresholds()
         [string]$TimeInterval   = $null
     );
 
+    # Fix possible numeric value comparison issues
+    $TestInput = Test-IcingaDecimal $InputValue;
+    $BaseInput = Test-IcingaDecimal $BaseValue;
+
+    if ($TestInput.Decimal) {
+        [decimal]$InputValue = [decimal]$TestInput.Value;
+    }
+    if ($BaseInput.Decimal) {
+        [decimal]$BaseValue = [decimal]$BaseInput.Value;
+    }
+
     $IcingaThresholds = New-Object -TypeName PSObject;
     $IcingaThresholds | Add-Member -MemberType NoteProperty -Name 'Value'           -Value $InputValue;
     $IcingaThresholds | Add-Member -MemberType NoteProperty -Name 'BaseValue'       -Value $BaseValue;
@@ -115,9 +126,10 @@ function Compare-IcingaPluginThresholds()
     $TempValue                        = (Convert-IcingaPluginThresholds -Threshold ([string]::Format('{0}{1}', $InputValue, $Unit)));
     $InputValue                       = $TempValue.Value;
     $TmpUnit                          = $TempValue.Unit;
+    $TestInput                        = Test-IcingaDecimal $InputValue;
 
-    if (Test-Numeric $InputValue) {
-        [decimal]$InputValue = [decimal]$InputValue;
+    if ($TestInput.Decimal) {
+        [decimal]$InputValue = [decimal]$TestInput.Value;
     }
 
     $IcingaThresholds.RawValue        = $InputValue;