diff --git a/docs/rh-log.txt b/docs/rh-log.txt
index bc5eafd8c4..f7bb2b44c4 100644
--- a/docs/rh-log.txt
+++ b/docs/rh-log.txt
@@ -1,3 +1,11 @@
+August 2, 2006
+- Fixed: The ACS VM made no checks for object files without strings, assuming
+  that if it didn't have any strings, then it didn't matter what it calculated
+  for the location of the string table because it would never be referenced.
+  While this is true for a script all by itself, it means a crash if you have
+  a map script without strings that imports a library with strings and the
+  library tries to use one of its strings.
+
 August 1, 2006
 - It turns out that the Visual C++ 2005 runtime calls IsDebuggerPresent, which
   is not available under Windows 95. Since this is (or at least should be) the
diff --git a/src/p_acs.cpp b/src/p_acs.cpp
index 143c4caa06..19ca624c5f 100644
--- a/src/p_acs.cpp
+++ b/src/p_acs.cpp
@@ -758,7 +758,15 @@ FBehavior::FBehavior (int lumpnum, FileReader * fr, int len)
 	else
 	{
 		UnencryptStrings ();
-		StringTable = FindChunk (MAKE_ID('S','T','R','L')) - Data + 8;
+		BYTE *strings = FindChunk (MAKE_ID('S','T','R','L'));
+		if (strings != NULL)
+		{
+			StringTable = strings - Data + 8;
+		}
+		else
+		{
+			StringTable = 0;
+		}
 	}
 
 	if (Format == ACS_Old)
@@ -1388,6 +1396,10 @@ const char *FBehavior::StaticLookupString (DWORD index)
 
 const char *FBehavior::LookupString (DWORD index) const
 {
+	if (StringTable == 0)
+	{
+		return NULL;
+	}
 	if (Format == ACS_Old)
 	{
 		DWORD *list = (DWORD *)(Data + StringTable);