diff --git a/Source/Private/GetBuildInfo.ps1 b/Source/Private/GetBuildInfo.ps1
index 458e6e3..bdebdff 100644
--- a/Source/Private/GetBuildInfo.ps1
+++ b/Source/Private/GetBuildInfo.ps1
@@ -77,16 +77,13 @@ function GetBuildInfo {
     }
     Write-Debug "Finished parsing Build Manifest $BuildManifest"
 
-    $BuildInfo = $BuildInfo | Update-Object $ParameterValues
-    Write-Debug "Using Module Manifest $($BuildInfo.SourcePath)"
-
     $BuildManifestParent = if ($BuildManifest) {
         Split-Path -Parent $BuildManifest
     } else {
         Get-Location -PSProvider FileSystem
     }
 
-    if (-Not $BuildInfo.SourcePath) {
+    if ((-not $BuildInfo.SourcePath) -and $ParameterValues["SourcePath"] -notmatch '\.psd1') {
         # Find a module manifest (or maybe several)
         $ModuleInfo = Get-ChildItem $BuildManifestParent -Recurse -Filter *.psd1 -ErrorAction SilentlyContinue |
             ImportModuleManifest -ErrorAction SilentlyContinue
@@ -102,13 +99,16 @@ function GetBuildInfo {
         }
         if (@($ModuleInfo).Count -eq 1) {
             Write-Debug "Updating BuildInfo SourcePath to $($ModuleInfo.Path)"
-            $BuildInfo = $BuildInfo | Update-Object @{ SourcePath = $ModuleInfo.Path }
+            $ParameterValues["SourcePath"] = $ModuleInfo.Path
         }
-        if (-Not $BuildInfo.SourcePath) {
+        if (-Not $ModuleInfo) {
             throw "Can't find a module manifest in $BuildManifestParent"
         }
     }
 
+    $BuildInfo = $BuildInfo | Update-Object $ParameterValues
+    Write-Debug "Using Module Manifest $($BuildInfo.SourcePath)"
+
     # Make sure the SourcePath is absolute and points at an actual file
     if (!(Split-Path -IsAbsolute $BuildInfo.SourcePath) -and $BuildManifestParent) {
         $BuildInfo.SourcePath = Join-Path $BuildManifestParent $BuildInfo.SourcePath | Convert-Path
diff --git a/Tests/Integration/Source1.Tests.ps1 b/Tests/Integration/Source1.Tests.ps1
index fab20ad..c32c291 100644
--- a/Tests/Integration/Source1.Tests.ps1
+++ b/Tests/Integration/Source1.Tests.ps1
@@ -88,7 +88,14 @@ Describe "Regression test for #84: Multiple Aliases per command will Export" -Ta
 }
 
 Describe "Supports building without a build.psd1" -Tag Integration {
-    Copy-Item  $PSScriptRoot\Source1 TestDrive:\Source1 -Recurse
+    Copy-Item $PSScriptRoot\Source1 TestDrive:\Source1 -Recurse
+    # This is the old build, with a build.psd1
+    $Output = Build-Module TestDrive:\Source1\build.psd1 -Passthru
+    $ManifestContent = Get-Content $Output.Path
+    $ModuleContent = Get-Content ([IO.Path]::ChangeExtension($Output.Path, ".psm1"))
+    Remove-Item (Split-Path $Output.Path) -Recurse
+
+    # Then remove the build.psd1 and rebuild it
     Remove-Item TestDrive:\Source1\build.psd1
 
     $Build = @{ }
@@ -105,6 +112,8 @@ Describe "Supports building without a build.psd1" -Tag Integration {
 
     It "Creates the same module as with a build.psd1" {
         $Build.Metadata = Import-Metadata $Build.Output.Path
+        Get-Content $Build.Output.Path | Should -Be $ManifestContent
+        Get-Content ([IO.Path]::ChangeExtension($Build.Output.Path, ".psm1")) | Should -Be $ModuleContent
     }
 
     It "Should update AliasesToExport in the manifest" {
@@ -115,6 +124,42 @@ Describe "Supports building without a build.psd1" -Tag Integration {
         $Build.Metadata.FunctionsToExport | Should -Be @("Get-Source", "Set-Source")
     }
 }
+Describe "Supports building discovering the module without a build.psd1" -Tag Integration {
+    Copy-Item $PSScriptRoot\Source1 TestDrive:\source -Recurse
+
+    # This is the old build, with a build.psd1
+    $Output = Build-Module TestDrive:\source\build.psd1 -Passthru
+    $ManifestContent = Get-Content $Output.Path
+    $ModuleContent = Get-Content ([IO.Path]::ChangeExtension($Output.Path, ".psm1"))
+    Remove-Item (Split-Path $Output.Path) -Recurse
+
+    # Then remove the build.psd1 and rebuild it
+    Remove-Item TestDrive:\source\build.psd1
+
+    Push-Location -StackName 'IntegrationTest' -Path TestDrive:\
+
+    $Build = @{ }
+
+    It "No longer fails if there's no build.psd1" {
+        $Build.Output = Build-Module -Passthru
+    }
+
+    It "Creates the same module as with a build.psd1" {
+        $Build.Metadata = Import-Metadata $Build.Output.Path
+        Get-Content $Build.Output.Path | Should -Be $ManifestContent
+        Get-Content ([IO.Path]::ChangeExtension($Build.Output.Path, ".psm1")) | Should -Be $ModuleContent
+    }
+
+    It "Should update AliasesToExport in the manifest" {
+        $Build.Metadata.AliasesToExport | Should -Be @("GS", "GSou", "SS", "SSou")
+    }
+
+    It "Should update FunctionsToExport in the manifest" {
+        $Build.Metadata.FunctionsToExport | Should -Be @("Get-Source", "Set-Source")
+    }
+
+    Pop-Location -StackName 'IntegrationTest'
+}
 
 Describe "Regression test for #88 not copying prefix files" -Tag Integration, Regression {
     $Output = Build-Module $PSScriptRoot\build.psd1 -Passthru