diff --git a/SabreTools.Serialization/Deserializers/PortableExecutable.cs b/SabreTools.Serialization/Deserializers/PortableExecutable.cs
index b5bb5ec4..906511dc 100644
--- a/SabreTools.Serialization/Deserializers/PortableExecutable.cs
+++ b/SabreTools.Serialization/Deserializers/PortableExecutable.cs
@@ -99,7 +99,8 @@ namespace SabreTools.Serialization.Deserializers
                     executable.COFFSymbolTable = ParseCOFFSymbolTable(data, coffFileHeader.NumberOfSymbols);
 
                     // Set the COFF string table
-                    executable.COFFStringTable = ParseCOFFStringTable(data);
+                    if (executable.COFFSymbolTable != null)
+                        executable.COFFStringTable = ParseCOFFStringTable(data);
                 }
 
                 #endregion
@@ -400,7 +401,7 @@ namespace SabreTools.Serialization.Deserializers
         /// <param name="data">Stream to parse</param>
         /// <param name="count">Number of COFF symbol table entries to read</param>
         /// <returns>Filled COFF symbol table on success, null on error</returns>
-        public static COFFSymbolTableEntry[] ParseCOFFSymbolTable(Stream data, uint count)
+        public static COFFSymbolTableEntry[]? ParseCOFFSymbolTable(Stream data, uint count)
         {
             var coffSymbolTable = new COFFSymbolTableEntry[count];
 
@@ -468,6 +469,10 @@ namespace SabreTools.Serialization.Deserializers
                     {
                         currentSymbolType = 6;
                     }
+                    else
+                    {
+                        return null;
+                    }
                 }
 
                 // Auxiliary Format 1: Function Definitions
@@ -543,6 +548,12 @@ namespace SabreTools.Serialization.Deserializers
                     auxSymbolsRemaining--;
                 }
 
+                // Invalid case, should never happen
+                else
+                {
+                    return null;
+                }
+
                 // If we hit the last aux symbol, go back to normal format
                 if (auxSymbolsRemaining == 0)
                     currentSymbolType = 0;