diff --git a/Makefile b/Makefile
index 71a9dbe..0c4403e 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
-CC = gcc
-CFLAGS = -O2 -Wall
+CC := gcc
+CFLAGS := -O2 -Wall
 
 # MAC_BUILD - set this to "universal" to build a 2-way fat library 
 MAC_BUILD = universal
@@ -20,7 +20,7 @@ endif
 
 ifeq ($(UNAME), SunOS)
 RANLIB=/bin/true
-PATH +=:/usr/perl5/5.10.0/bin:/usr/perl5/5.12/bin
+PATH := $(PATH):/usr/perl5/5.10.0/bin:/usr/perl5/5.12/bin
 CFLAGS += -fPIC
 ifeq ($(ARCH), i86pc)
 ARCH = $(shell isainfo -k)
diff --git a/usdt_dof_file.c b/usdt_dof_file.c
index 1c0b4f8..108c1d3 100644
--- a/usdt_dof_file.c
+++ b/usdt_dof_file.c
@@ -184,7 +184,8 @@ usdt_dof_file_load(usdt_dof_file_t *file, const char *module)
 #if __FreeBSD__ >= 11
         dh.dofhp_pid = getpid();
 #endif
-        (void) strncpy(dh.dofhp_mod, module, sizeof (dh.dofhp_mod));
+        (void) strncpy(dh.dofhp_mod, module, sizeof (dh.dofhp_mod) - 1);
+        dh.dofhp_mod[sizeof (dh.dofhp_mod) - 1] = '\0';
 
         if ((fd = open(helper, O_RDWR)) < 0)
                 return (-1);