diff --git a/src/CHANGELOG b/src/CHANGELOG
index f2febb1c3..d7b504bc6 100644
--- a/src/CHANGELOG
+++ b/src/CHANGELOG
@@ -123,6 +123,10 @@ ECL 0.9f
 
  - When *PRINT-READABLY*=T, vectors just print as arrays.
 
+ - When used as macro characters, upper and lowercase letters share the same
+   dispatcher, so that if the user defines a dispatcher for #f, it is
+   automagically set for #F and viceversa.
+
 * MOP Compatibility:
 
  - We have implemented the *-SLOT-DEFINITION classes, as well as the protocol
diff --git a/src/c/read.d b/src/c/read.d
index 2ec0ff537..201e60f45 100644
--- a/src/c/read.d
+++ b/src/c/read.d
@@ -1745,9 +1745,12 @@ ecl_invalid_character_p(int c)
 	if (entry->macro != cl_core.dispatch_reader || entry->dispatch_table == NULL)
 		FEerror("~S is not a dispatch character.", 1, dspchr);
 	subcode = char_code(subchr);
-	if (islower(subcode))
-		subcode = toupper(subcode);
 	entry->dispatch_table[subcode] = fnc;
+	if (islower(subcode)) {
+		entry->dispatch_table[toupper(subcode)] = fnc;
+	} else if (isupper(subcode)) {
+		entry->dispatch_table[tolower(subcode)] = fnc;
+	}
 	@(return Ct)
 @)