diff --git a/src/handle_check_address.c b/src/handle_check_address.c
index 41339b8..e89a96a 100644
--- a/src/handle_check_address.c
+++ b/src/handle_check_address.c
@@ -6,14 +6,13 @@
 
 #define ZERO(x) memset(x, 0, sizeof(x))
 
-void handle_check_address(check_address_parameters_t* params, chain_config_t* chain_config) {
+int handle_check_address(check_address_parameters_t* params, chain_config_t* chain_config) {
     PRINTF("Params on the address %d\n", (unsigned int) params);
     PRINTF("Address to check %s\n", params->address_to_check);
     PRINTF("Inside handle_check_address\n");
-    params->result = 0;
     if (params->address_to_check == 0) {
         PRINTF("Address to check == 0\n");
-        return;
+        return 0;
     }
 
     uint8_t i;
@@ -35,7 +34,7 @@ void handle_check_address(check_address_parameters_t* params, chain_config_t* ch
     if ((bip32PathLength < 0x01) || (bip32PathLength > MAX_BIP32_PATH) ||
         (bip32PathLength * 4 != params->address_parameters_length - 1)) {
         PRINTF("Invalid path\n");
-        return;
+        return 0;
     }
     for (i = 0; i < bip32PathLength; i++) {
         locals_union1.bip32Path[i] = U4BE(bip32_path_ptr, 0);
@@ -70,8 +69,8 @@ void handle_check_address(check_address_parameters_t* params, chain_config_t* ch
                params->address_to_check + offset_0x,
                strlen(locals_union1.address)) != 0) {
         PRINTF("Addresses doesn't match\n");
-        return;
+        return 0;
     }
     PRINTF("Addresses  match\n");
-    params->result = 1;
+    return 1;
 }
diff --git a/src/handle_check_address.h b/src/handle_check_address.h
index b3ac25f..4267a30 100644
--- a/src/handle_check_address.h
+++ b/src/handle_check_address.h
@@ -4,7 +4,7 @@
 #include "swap_lib_calls.h"
 #include "chainConfig.h"
 
-void handle_check_address(check_address_parameters_t* check_address_params,
-                          chain_config_t* chain_config);
+int handle_check_address(check_address_parameters_t* check_address_params,
+                         chain_config_t* chain_config);
 
 #endif  // _HANDLE_CHECK_ADDRESS_H_
\ No newline at end of file
diff --git a/src/handle_get_printable_amount.c b/src/handle_get_printable_amount.c
index 0ede372..b59dbf9 100644
--- a/src/handle_get_printable_amount.c
+++ b/src/handle_get_printable_amount.c
@@ -6,21 +6,20 @@
 #include "string.h"
 #include <stdint.h>
 
-void handle_get_printable_amount(get_printable_amount_parameters_t* params,
-                                 chain_config_t* config) {
+int handle_get_printable_amount(get_printable_amount_parameters_t* params, chain_config_t* config) {
     uint8_t decimals;
     char ticker[MAX_TICKER_LEN];
     memset(params->printable_amount, 0, sizeof(params->printable_amount));
     if (params->amount_length > 32) {
         PRINTF("Amount is too big, 32 bytes max but buffer has %u bytes", params->amount_length);
-        os_lib_end();
+        return 0;
     }
     if (!parse_swap_config(params->coin_configuration,
                            params->coin_configuration_length,
                            ticker,
                            &decimals)) {
         PRINTF("Error while parsing config\n");
-        os_lib_end();
+        return 0;
     }
 
     // If the amount is a fee, its value is nominated in ETH even if we're doing an ERC20 swap
@@ -38,4 +37,5 @@ void handle_get_printable_amount(get_printable_amount_parameters_t* params,
                    ticker,
                    params->printable_amount,
                    sizeof(params->printable_amount));
+    return 1;
 }
diff --git a/src/handle_get_printable_amount.h b/src/handle_get_printable_amount.h
index 622e3fe..0bf2015 100644
--- a/src/handle_get_printable_amount.h
+++ b/src/handle_get_printable_amount.h
@@ -4,7 +4,7 @@
 #include "swap_lib_calls.h"
 #include "chainConfig.h"
 
-void handle_get_printable_amount(get_printable_amount_parameters_t* get_printable_amount_params,
-                                 chain_config_t* config);
+int handle_get_printable_amount(get_printable_amount_parameters_t* get_printable_amount_params,
+                                chain_config_t* config);
 
 #endif  // _HANDLE_GET_PRINTABLE_AMOUNT_H_
\ No newline at end of file
diff --git a/src/handle_swap_sign_transaction.c b/src/handle_swap_sign_transaction.c
index 244fa40..ebb0040 100644
--- a/src/handle_swap_sign_transaction.c
+++ b/src/handle_swap_sign_transaction.c
@@ -4,7 +4,7 @@
 #include "shared_context.h"
 #include "utils.h"
 
-void copy_transaction_parameters(create_transaction_parameters_t* sign_transaction_params,
+bool copy_transaction_parameters(create_transaction_parameters_t* sign_transaction_params,
                                  chain_config_t* config) {
     // first copy parameters to stack, and then to global data.
     // We need this "trick" as the input data position can overlap with app-ethereum globals
@@ -16,7 +16,7 @@ void copy_transaction_parameters(create_transaction_parameters_t* sign_transacti
     if ((stack_data.fullAddress[sizeof(stack_data.fullAddress) - 1] != '\0') ||
         (sign_transaction_params->amount_length > 32) ||
         (sign_transaction_params->fee_amount_length > 8)) {
-        os_lib_end();
+        return false;
     }
 
     uint8_t decimals;
@@ -26,7 +26,7 @@ void copy_transaction_parameters(create_transaction_parameters_t* sign_transacti
                            ticker,
                            &decimals)) {
         PRINTF("Error while parsing config\n");
-        os_lib_end();
+        return false;
     }
     amountToString(sign_transaction_params->amount,
                    sign_transaction_params->amount_length,
@@ -46,11 +46,10 @@ void copy_transaction_parameters(create_transaction_parameters_t* sign_transacti
                    sizeof(stack_data.maxFee));
 
     memcpy(&strings.common, &stack_data, sizeof(stack_data));
+    return true;
 }
 
-void handle_swap_sign_transaction(create_transaction_parameters_t* sign_transaction_params,
-                                  chain_config_t* config) {
-    copy_transaction_parameters(sign_transaction_params, config);
+void handle_swap_sign_transaction(chain_config_t* config) {
     chainConfig = config;
     reset_app_context();
     called_from_swap = true;
diff --git a/src/handle_swap_sign_transaction.h b/src/handle_swap_sign_transaction.h
index ddf2379..21b52c3 100644
--- a/src/handle_swap_sign_transaction.h
+++ b/src/handle_swap_sign_transaction.h
@@ -4,7 +4,9 @@
 #include "swap_lib_calls.h"
 #include "chainConfig.h"
 
-void handle_swap_sign_transaction(create_transaction_parameters_t* get_printable_amount_params,
-                                  chain_config_t* config);
+bool copy_transaction_parameters(create_transaction_parameters_t* sign_transaction_params,
+                                 chain_config_t* config);
+
+void handle_swap_sign_transaction(chain_config_t* config);
 
 #endif  // _HANDLE_SWAP_SIGN_TRANSACTION_H_
\ No newline at end of file