diff --git a/libr/asm/asm.c b/libr/asm/asm.c
index a5c2fb1398..ff49cfcf2d 100644
--- a/libr/asm/asm.c
+++ b/libr/asm/asm.c
@@ -303,7 +303,9 @@ static int has_bits(RAsmPlugin *h, int bits) {
 }
 
 R_API void r_asm_set_cpu(RAsm *a, const char *cpu) {
-	free (a->cpu);
+	if (a) {
+		free (a->cpu);
+	}
 	a->cpu = cpu? strdup (cpu): NULL;
 }
 
diff --git a/libr/core/cconfig.c b/libr/core/cconfig.c
index 040c35c0b3..f8f23b1540 100755
--- a/libr/core/cconfig.c
+++ b/libr/core/cconfig.c
@@ -268,7 +268,9 @@ static int cb_asmarch(void *user, void *data) {
 		eprintf ("asm.arch: cannot find (%s)\n", node->value);
 		return false;
 	}
-	const char *asm_cpu = r_config_get (core->config, "asm.cpu");
+	//we should strdup here otherwise will crash if any r_config_set
+	//free the old value
+	char *asm_cpu = strdup (r_config_get (core->config, "asm.cpu"));
 	if (core->assembler->cur) {
 		const char *newAsmCPU = core->assembler->cur->cpus;
 		if (newAsmCPU) {
@@ -351,6 +353,7 @@ static int cb_asmarch(void *user, void *data) {
 		core->print->big_endian = bigbin;
 	}
 	r_asm_set_cpu (core->assembler, asm_cpu);
+	free (asm_cpu);
 	/* reload types and cc info */
 	r_core_anal_type_init (core);
 	r_core_anal_cc_init (core);