diff --git a/makepanda/makepanda.py b/makepanda/makepanda.py
index a07ad63ba9..88735bc34a 100755
--- a/makepanda/makepanda.py
+++ b/makepanda/makepanda.py
@@ -1664,7 +1664,7 @@ def CompileFlex(wobj,wsrc,opts):
     dashi = opts.count("FLEXDASHI")
     flex = GetFlex()
     want_version = GetValueOption(opts, "FLEXVERSION:")
-    if want_version:
+    if flex and want_version:
         # Is flex at the required version for this file?
         want_version = tuple(map(int, want_version.split('.')))
         have_version = GetFlexVersion()
diff --git a/makepanda/makepandacore.py b/makepanda/makepandacore.py
index 20f63577c8..9cac107de1 100644
--- a/makepanda/makepandacore.py
+++ b/makepanda/makepandacore.py
@@ -556,7 +556,7 @@ def GetFlex():
 def GetFlexVersion():
     flex = GetFlex()
     if not flex:
-        return None
+        return (0, 0, 0)
 
     try:
         handle = subprocess.Popen(["flex", "--version"], executable=flex, stdout=subprocess.PIPE)