diff --git a/src/core/cfg.lex b/src/core/cfg.lex
index b8e4f9aa700..d36fc72b544 100644
--- a/src/core/cfg.lex
+++ b/src/core/cfg.lex
@@ -1927,11 +1927,16 @@ ksr_ppdefine_t* pp_get_define(int idx)
 	return &pp_defines[idx];
 }
 
-static int pp_lookup(int len, const char * text)
+static int pp_lookup(int len, const char *text)
 {
 	str var = {(char *)text, len};
 	int i;
 
+	if(len<=0 || text==NULL) {
+		LM_ERR("invalid parameters");
+		return -1;
+	}
+
 	for (i=0; i<pp_num_defines; i++)
 		if (STR_EQ(pp_defines[i].name, var))
 			return i;
@@ -1945,10 +1950,15 @@ int pp_define_set_type(int type)
 	return 0;
 }
 
-int pp_define(int len, const char * text)
+int pp_define(int len, const char *text)
 {
 	int ppos;
 
+	if(len<=0 || text==NULL) {
+		LM_ERR("invalid parameters");
+		return -1;
+	}
+
 	LM_DBG("defining id: %.*s\n", len, text);
 
 	if (pp_num_defines == MAX_DEFINES) {
@@ -2010,7 +2020,7 @@ int pp_define_set(int len, char *text)
 		LM_BUG("BUG: the index in define table not set yet\n");
 		return -1;
 	}
-	if(len<=0) {
+	if(len<=0 || text==NULL) {
 		LM_DBG("no define value - ignoring\n");
 		return 0;
 	}
@@ -2046,7 +2056,7 @@ int pp_define_set(int len, char *text)
 	return 0;
 }
 
-int pp_define_env(const char * text, int len)
+int pp_define_env(const char *text, int len)
 {
 	char *r;
 	str defname;
@@ -2087,7 +2097,7 @@ int pp_define_env(const char * text, int len)
 	return 0;
 }
 
-str *pp_define_get(int len, const char * text)
+str *pp_define_get(int len, const char *text)
 {
 	str var = {(char *)text, len};
 	int i;
@@ -2129,7 +2139,7 @@ static int pp_ifdef_type(int type)
  * ifndef defined   -> 0
  * ifndef undefined -> 1
  */
-static void pp_ifdef_var(int len, const char * text)
+static void pp_ifdef_var(int len, const char *text)
 {
 	pp_ifdef_stack[pp_sptr] ^= (pp_lookup(len, text) < 0);
 }
diff --git a/src/main.c b/src/main.c
index ee558db13f4..6d363ba3751 100644
--- a/src/main.c
+++ b/src/main.c
@@ -2202,16 +2202,17 @@ int main(int argc, char** argv)
 			case 'A':
 					p = strchr(optarg, '=');
 					if(p) {
-						*p = '\0';
+						tmp_len = p - optarg;
+					} else {
+						tmp_len = strlen(optarg);
 					}
 					pp_define_set_type(0);
-					if(pp_define(strlen(optarg), optarg)<0) {
+					if(pp_define(tmp_len, optarg)<0) {
 						fprintf(stderr, "error at define param: -A %s\n",
 								optarg);
 						goto error;
 					}
 					if(p) {
-						*p = '=';
 						p++;
 						if(pp_define_set(strlen(p), p)<0) {
 							fprintf(stderr, "error at define value: -A %s\n",