diff --git a/.vscode/tasks.json b/.vscode/tasks.json
index b90945e..9f7a98c 100644
--- a/.vscode/tasks.json
+++ b/.vscode/tasks.json
@@ -6,6 +6,22 @@
         {
             "label": "Build",
             "type": "process",
+            "command": "powershell",
+            "args": ["-noprofile","-command","Invoke-Build","-File","./invoke.build.ps1","-Author","'codaamok'","-ModuleName","'PSBusinessTime'"],
+            "group": "build",
+            "presentation": {
+                "echo": true,
+                "reveal": "always",
+                "focus": false,
+                "panel": "shared",
+                "showReuseMessage": true,
+                "clear": false
+            },
+            "problemMatcher": []
+        },
+        {
+            "label": "Build (pwsh)",
+            "type": "process",
             "command": "pwsh",
             "args": ["-noprofile","-command","Invoke-Build","-File","./invoke.build.ps1","-Author","'codaamok'","-ModuleName","'PSBusinessTime'"],
             "group": "build",
@@ -22,6 +38,25 @@
         {
             "label": "Build (with docs)",
             "type": "process",
+            "command": "powershell",
+            "args": ["-noprofile","-command","Invoke-Build","-File","./invoke.build.ps1","-Author","'codaamok'","-ModuleName","'PSBusinessTime'","-UpdateDocs","$true"],
+            "group": {
+                "kind": "build",
+                "isDefault": true
+            },
+            "presentation": {
+                "echo": true,
+                "reveal": "always",
+                "focus": false,
+                "panel": "shared",
+                "showReuseMessage": true,
+                "clear": false
+            },
+            "problemMatcher": []
+        },
+        {
+            "label": "Build (with pwsh & docs)",
+            "type": "process",
             "command": "pwsh",
             "args": ["-noprofile","-command","Invoke-Build","-File","./invoke.build.ps1","-Author","'codaamok'","-ModuleName","'PSBusinessTime'","-UpdateDocs","$true"],
             "group": {
@@ -39,7 +74,7 @@
             "problemMatcher": []
         },
         {
-            "label": "Tests",
+            "label": "Tests (with pwsh)",
             "type": "process",
             "command": "pwsh",
             "args": ["-noprofile", "-file", "./tests/invoke.tests.ps1"],
@@ -57,5 +92,24 @@
             },
             "problemMatcher": []
         },
+        {
+            "label": "Tests",
+            "type": "process",
+            "command": "powershell",
+            "args": ["-noprofile", "-file", "./tests/invoke.tests.ps1"],
+            "group": {
+                "kind": "test",
+                "isDefault": true
+            },
+            "presentation": {
+                "echo": true,
+                "reveal": "always",
+                "focus": false,
+                "panel": "shared",
+                "showReuseMessage": true,
+                "clear": false
+            },
+            "problemMatcher": []
+        },
     ]
 }
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 61e4df5..f1c7e8f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Fixed
+- `New-BusinessTimeSpan` threw an exception in some scenarios for Windows PowerShell - see issue #1
 
 ## [0.3.0] - 2022-05-04
 ### Changed
diff --git a/src/Public/New-BusinessTimeSpan.ps1 b/src/Public/New-BusinessTimeSpan.ps1
index f3e4157..c3a0a64 100644
--- a/src/Public/New-BusinessTimeSpan.ps1
+++ b/src/Public/New-BusinessTimeSpan.ps1
@@ -194,7 +194,7 @@ function New-BusinessTimeSpan {
             $NumberOfWorkingDays--
         }
 
-        $InBetweenHours = $NumberOfWorkingDays * $WorkingHours
+        $InBetweenHours = New-TimeSpan -Seconds ($NumberOfWorkingDays * $WorkingHours.TotalSeconds)
         $InBetweenHours + $ElapsedTime
     }
 }
\ No newline at end of file
diff --git a/tests/Public/New-BusinessTimeSpan.Tests.ps1 b/tests/Public/New-BusinessTimeSpan.Tests.ps1
index 36bb804..1e3b0f2 100644
--- a/tests/Public/New-BusinessTimeSpan.Tests.ps1
+++ b/tests/Public/New-BusinessTimeSpan.Tests.ps1
@@ -63,7 +63,7 @@ Describe "New-BusinessTimeSpan" {
         It "should be 143 minutes, across 2 consecutive days, where 1 is a working days" {
             $StartDate = Get-Date '2022-04-10 13:52:12'
             $EndDate   = Get-Date '2022-04-11 10:23:12'
-            (New-BusinessTimeSpan -Start $StartDate -End $EndDate).TotalMinutes | Should -Be 143.2
+            [decimal](New-BusinessTimeSpan -Start $StartDate -End $EndDate).TotalMinutes | Should -Be 143.2
         }
     
         It "should be 10 hours, across 1 full day and 1 partial day, where both are working days" {