diff --git a/Makefile b/Makefile
index 168dff8..a786538 100644
--- a/Makefile
+++ b/Makefile
@@ -25,7 +25,7 @@ endif
 LIBUCONTEXT_C_SRC = $(wildcard arch/${ARCH}/*.c)
 LIBUCONTEXT_S_SRC = $(wildcard arch/${ARCH}/*.S)
 
-LIBUCONTEXT_VERSION = 0.13
+LIBUCONTEXT_VERSION := 0.13
 LIBUCONTEXT_OBJ = ${LIBUCONTEXT_C_SRC:.c=.o} ${LIBUCONTEXT_S_SRC:.S=.o}
 LIBUCONTEXT_SOVERSION = 0
 LIBUCONTEXT_NAME = libucontext.so