diff --git a/src/eth_plugin_handler.c b/src/eth_plugin_handler.c
index 930182c..09c1602 100644
--- a/src/eth_plugin_handler.c
+++ b/src/eth_plugin_handler.c
@@ -63,6 +63,17 @@ eth_plugin_result_t eth_plugin_perform_init(uint8_t *contractAddress,
 
     PRINTF("Selector %.*H\n", 4, init->selector);
     if (tmpCtx.transactionContext.externalPluginIsSet) {
+        // check if the registered external plugin matches the TX contract address / method selector
+        if (memcmp(contractAddress,
+                   dataContext.tokenContext.contract_address,
+                   sizeof(dataContext.tokenContext.contract_address)) != 0) {
+            os_sched_exit(0);
+        }
+        if (memcmp(init->selector,
+                   dataContext.tokenContext.method_selector,
+                   sizeof(dataContext.tokenContext.method_selector)) != 0) {
+            os_sched_exit(0);
+        }
         PRINTF("External plugin will be used\n");
         dataContext.tokenContext.pluginStatus = ETH_PLUGIN_RESULT_OK;
         contractAddress = NULL;
diff --git a/src/shared_context.h b/src/shared_context.h
index 2259398..3c46460 100644
--- a/src/shared_context.h
+++ b/src/shared_context.h
@@ -58,7 +58,13 @@ typedef struct tokenContext_t {
     uint8_t pluginUiCurrentItem;
     uint8_t pluginUiState;
 
-    uint8_t pluginContext[3 * 32];
+    union {
+        struct {
+            uint8_t contract_address[20];
+            uint8_t method_selector[4];
+        };
+        uint8_t pluginContext[3 * 32];
+    };
 
 #ifdef HAVE_STARKWARE
     uint8_t quantum[32];
diff --git a/src_features/setExternalPlugin/cmd_setExternalPlugin.c b/src_features/setExternalPlugin/cmd_setExternalPlugin.c
index b5748f7..af1bb4a 100644
--- a/src_features/setExternalPlugin/cmd_setExternalPlugin.c
+++ b/src_features/setExternalPlugin/cmd_setExternalPlugin.c
@@ -2,6 +2,9 @@
 #include "apdu_constants.h"
 #include "ui_flow.h"
 
+#define CONTRACT_ADDR_SIZE 20
+#define SELECTOR_SIZE      4
+
 void handleSetExternalPlugin(uint8_t p1,
                              uint8_t p2,
                              uint8_t *workBuffer,
@@ -11,9 +14,9 @@ void handleSetExternalPlugin(uint8_t p1,
     UNUSED(p1);
     UNUSED(p2);
     UNUSED(flags);
-    uint8_t pluginNameLength = dataLength;
+    uint8_t pluginNameLength = *workBuffer++;
 
-    if (dataLength < 1) {
+    if (dataLength < 1 || dataLength != 1 + pluginNameLength + CONTRACT_ADDR_SIZE + SELECTOR_SIZE) {
         THROW(0x6A80);
     }
 
@@ -23,6 +26,7 @@ void handleSetExternalPlugin(uint8_t p1,
 
     memmove(dataContext.tokenContext.pluginName, workBuffer, pluginNameLength);
     dataContext.tokenContext.pluginName[pluginNameLength] = '\0';
+    workBuffer += pluginNameLength;
 
     PRINTF("Check external plugin %s\n", dataContext.tokenContext.pluginName);
 
@@ -36,6 +40,9 @@ void handleSetExternalPlugin(uint8_t p1,
         }
         CATCH_OTHER(e) {
             PRINTF("%s external plugin is not present\n", dataContext.tokenContext.pluginName);
+            memset(dataContext.tokenContext.pluginName,
+                   sizeof(dataContext.tokenContext.pluginName),
+                   0);
             THROW(0x6984);
         }
         FINALLY {
@@ -43,9 +50,13 @@ void handleSetExternalPlugin(uint8_t p1,
     }
     END_TRY;
 
-    tmpCtx.transactionContext.externalPluginIsSet = true;
     PRINTF("Plugin found\n");
 
+    memmove(dataContext.tokenContext.contract_address, workBuffer, CONTRACT_ADDR_SIZE);
+    workBuffer += 20;
+    memmove(dataContext.tokenContext.method_selector, workBuffer, SELECTOR_SIZE);
+    tmpCtx.transactionContext.externalPluginIsSet = true;
+
     G_io_apdu_buffer[(*tx)++] = 0x90;
     G_io_apdu_buffer[(*tx)++] = 0x00;
 }
\ No newline at end of file