diff --git a/RdlEngine/Definition/ReportParameter.cs b/RdlEngine/Definition/ReportParameter.cs
index 8a25048c..41b869bf 100644
--- a/RdlEngine/Definition/ReportParameter.cs
+++ b/RdlEngine/Definition/ReportParameter.cs
@@ -495,10 +495,16 @@ private object GetDataValueFromDisplay(object dvalue)
 
 		/// <summary>
 		/// The runtime value of the parameter.
+		/// Prefer using GetValueAsync() to avoid synchronous blocking on an async call.
 		/// </summary>
 		public object Value
 		{
-			get { return _rp.GetRuntimeValue(this._rpt); }
+            get
+            {
+                // HACK: async - synchronous wrapper needed for property getter;
+                // use GetValueAsync() when an async context is available.
+                return Task.Run(async () => await _rp.GetRuntimeValue(this._rpt)).GetAwaiter().GetResult();
+            }
 			set 
 			{
                 if (this.MultiValue && value is string)
@@ -513,6 +519,15 @@ public object Value
 			}
 		}
 
+        /// <summary>
+        /// Asynchronously gets the runtime value of the parameter.
+        /// Prefer this over the synchronous Value getter when an async context is available.
+        /// </summary>
+        public async Task<object> GetValueAsync()
+        {
+            return await _rp.GetRuntimeValue(this._rpt);
+        }
+
         /// <summary>
         /// Take a string and parse it into multiple values
         /// </summary>
diff --git a/RdlViewer/RdlViewer.cs b/RdlViewer/RdlViewer.cs
index 05c00c07..1885a7b6 100644
--- a/RdlViewer/RdlViewer.cs
+++ b/RdlViewer/RdlViewer.cs
@@ -900,7 +900,7 @@ public async Task SaveAs(string FileName, Majorsilence.Reporting.Rdl.OutputPrese
             if (!(type == OutputPresentationType.PDF || type == OutputPresentationType.PDFOldStyle ||
                 type == OutputPresentationType.TIF || type == OutputPresentationType.TIFBW))
             {
-                var ld = GetParameters();        // split parms into dictionary
+                var ld = await GetParameters();        // split parms into dictionary
                 await _Report.RunGetData(ld);                     // obtain the data (again)
             }
             try
@@ -1445,7 +1445,7 @@ private async Task<Pages> GetPages(Report report)
         {
             Pages pgs = null;
 
-            var ld = GetParameters();        // split parms into dictionary
+            var ld = await GetParameters();        // split parms into dictionary
 
             try
             {
@@ -1479,8 +1479,33 @@ private async Task<Pages> GetPages(Report report)
             return pgs;
         }
 
-        private IDictionary GetParameters()
+        private async Task<IDictionary> GetParameters()
         {
+            // If we have a loaded report with user parameters, use those runtime values
+            // instead of the _Parameters dictionary which may be stale
+            if (_Report != null && _Report.UserReportParameters != null && _Report.UserReportParameters.Count > 0)
+            {
+                Dictionary<string, object> runtimeParams = new Dictionary<string, object>();
+                foreach (UserReportParameter urp in _Report.UserReportParameters)
+                {
+                    // Always include user parameters, even when the value is null, so that
+                    // stale values from _Parameters cannot override user-visible parameters.
+                    runtimeParams[urp.Name] = await urp.GetValueAsync();
+                }
+                // Merge with any parameters from _Parameters that aren't in UserReportParameters
+                if (_Parameters != null)
+                {
+                    foreach (DictionaryEntry kvp in _Parameters)
+                    {
+                        string key = kvp.Key.ToString();
+                        if (!runtimeParams.ContainsKey(key))
+                        {
+                            runtimeParams[key] = kvp.Value;
+                        }
+                    }
+                }
+                return runtimeParams;
+            }
             return _Parameters;
         }