diff --git a/src/preserves/pegs.nim b/src/preserves/pegs.nim
index 421e4e5..86b81f5 100644
--- a/src/preserves/pegs.nim
+++ b/src/preserves/pegs.nim
@@ -39,7 +39,7 @@ grammar "Preserves":
   exp <- 'e' * ?('-'|'+') * +Digit
   flt <- int * ((frac * exp) | frac | exp)
 
-  Float <- >flt * 'f'
+  Float <- >flt * {'f','F'}
   Double <- flt
 
   SignedInteger <- int