Bump $(RELEASE).
diff --git a/Doc/Makefile b/Doc/Makefile
index 78ee92f..39e286d 100644
--- a/Doc/Makefile
+++ b/Doc/Makefile
@@ -56,7 +56,7 @@
 INFODIR=	info
 TOOLSDIR=	tools
 
-RELEASE=1.5.2a2
+RELEASE=1.5.2b1
 VERSION=1.5
 
 # These must be declared phony since there