diff --git a/Engine/ScriptAnalyzer.cs b/Engine/ScriptAnalyzer.cs
index b39db8b87..4d9eacc63 100644
--- a/Engine/ScriptAnalyzer.cs
+++ b/Engine/ScriptAnalyzer.cs
@@ -1455,6 +1455,28 @@ private Tuple<List<SuppressedRecord>, List<DiagnosticRecord>> SuppressRule(
             return records;
         }
 
+        /// <summary>
+        /// Wrapper around SuppressRule method.
+        ///
+        /// This enables suppressing external rules (written in PowerShell).
+        /// Since there can be an inconsistency between the rule name in
+        /// diagnostic record and the actual rule (function) name, we use
+        /// the diagnostic record rule name for suppression
+        /// </summary>
+        /// <param name="ruleSuppressions"></param>
+        /// <param name="ruleDiagnosticRecord"></param>
+        /// <returns>Returns a tuple of suppressed and diagnostic records</returns>
+        private Tuple<List<SuppressedRecord>, List<DiagnosticRecord>> SuppressRule(
+            Dictionary<string, List<RuleSuppression>> ruleSuppressions,
+            DiagnosticRecord ruleDiagnosticRecord
+            )
+        {
+            return SuppressRule(
+                ruleDiagnosticRecord.RuleName,
+                ruleSuppressions,
+                new List<DiagnosticRecord> { ruleDiagnosticRecord });
+        }
+
         /// <summary>
         /// Analyzes the syntax tree of a script file that has already been parsed.
         /// </summary>
@@ -1752,13 +1774,21 @@ public IEnumerable<DiagnosticRecord> AnalyzeSyntaxTree(
                     }
                 }
 
-                foreach (var record in this.GetExternalRecord(scriptAst, scriptTokens, exRules.ToArray(), fileName))
+                foreach (var ruleRecord in this.GetExternalRecord(scriptAst, scriptTokens, exRules.ToArray(), fileName))
                 {
-                    diagnostics.Add(record);
+                    var records = SuppressRule(ruleSuppressions, ruleRecord);
+                    foreach (var record in records.Item2)
+                    {
+                        diagnostics.Add(record);
+                    }
+                    foreach (var suppressedRec in records.Item1)
+                    {
+                        suppressed.Add(suppressedRec);
+                    }
                 }
             }
-
-#endregion
+            
+            #endregion
 
             // Need to reverse the concurrentbag to ensure that results are sorted in the increasing order of line numbers
             IEnumerable<DiagnosticRecord> diagnosticsList = diagnostics.Reverse();
diff --git a/Tests/Engine/RuleSuppression.tests.ps1 b/Tests/Engine/RuleSuppression.tests.ps1
index 0ad171eab..3f31e4619 100644
--- a/Tests/Engine/RuleSuppression.tests.ps1
+++ b/Tests/Engine/RuleSuppression.tests.ps1
@@ -114,13 +114,29 @@ function SuppressPwdParam()
 
     if (!$testingLibraryUsage)
     {
-	Context "Bad Rule Suppression" {
-    		It "Throws a non-terminating error" {
-	   	   Invoke-ScriptAnalyzer -ScriptDefinition $ruleSuppressionBad -IncludeRule "PSAvoidUsingUserNameAndPassWordParams" -ErrorVariable errorRecord -ErrorAction SilentlyContinue
-	   	   $errorRecord.Count | Should Be 1
-	   	   $errorRecord.FullyQualifiedErrorId | Should match "suppression message attribute error"
-	}
-    }
+        Context "Bad Rule Suppression" {
+            It "Throws a non-terminating error" {
+                Invoke-ScriptAnalyzer -ScriptDefinition $ruleSuppressionBad -IncludeRule "PSAvoidUsingUserNameAndPassWordParams" -ErrorVariable errorRecord -ErrorAction SilentlyContinue
+                $errorRecord.Count | Should Be 1
+                $errorRecord.FullyQualifiedErrorId | Should match "suppression message attribute error"
+            }
+        }
+
+        Context "External Rule Suppression" {
+            $externalRuleSuppression = @'
+[System.Diagnostics.CodeAnalysis.SuppressMessageAttribute('CommunityAnalyzerRules\Measure-WriteHost','')]
+param() # without the param block, powershell parser throws up!
+Write-Host "write-host"
+'@
+            It "Suppresses violation of an external ast rule" {
+                Invoke-ScriptAnalyzer `
+                    -ScriptDefinition $externalRuleSuppression `
+                    -CustomRulePath (Join-Path $directory "CommunityAnalyzerRules") `
+                    -OutVariable ruleViolations `
+                    -SuppressedOnly
+                $ruleViolations.Count | Should Be 1
+            }
+        }
     }
 }
 
diff --git a/build.ps1 b/build.ps1
index 22d1337d0..9af1a0d60 100644
--- a/build.ps1
+++ b/build.ps1
@@ -110,8 +110,12 @@ if ($BuildDocs)
     New-ExternalHelp -Path $markdownDocsPath -OutputPath $outputDocsPath -Force -Verbose:$verbosity
 }
 
-
-$moduleRootPath = Join-Path (Split-Path $profile) 'Modules'
+# Appveyor errors out due to $profile being null. Hence...
+$moduleRootPath = "$HOME/Documents/WindowsPowerShell/Modules"
+if ($profile -ne $null)
+{
+    $moduleRootPath = Join-Path (Split-Path $profile) 'Modules'
+}
 $modulePSSAPath = Join-Path $moduleRootPath 'PSScriptAnalyzer'
 if ($Install)
 {