diff --git a/armsrc/Standalone/hf_msdsal.c b/armsrc/Standalone/hf_msdsal.c
index 85f7edf8e..be66e39a6 100644
--- a/armsrc/Standalone/hf_msdsal.c
+++ b/armsrc/Standalone/hf_msdsal.c
@@ -183,8 +183,8 @@ void RunMod(void) {
     uint8_t receivedCmd[MAX_FRAME_SIZE] = { 0x00 };
     uint8_t receivedCmdPar[MAX_PARITY_SIZE] = { 0x00 };
 
-    uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
-    uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
+    uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE] = {0};
+    uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE] = {0};
 
     // to know the transaction status
     uint8_t prevCmd = 0;
diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c
index a793664e0..1d2ed655a 100644
--- a/armsrc/iso14443a.c
+++ b/armsrc/iso14443a.c
@@ -1150,8 +1150,8 @@ void SimulateIso14443aTag(uint8_t tagType, uint8_t flags, uint8_t *data) {
     // Such a response is less time critical, so we can prepare them on the fly
 #define DYNAMIC_RESPONSE_BUFFER_SIZE 64
 #define DYNAMIC_MODULATION_BUFFER_SIZE 512
-    uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
-    uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
+    uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE] = {0};
+    uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE] = {0};
     tag_response_info_t dynamic_response_info = {
         .response = dynamic_response_buffer,
         .response_n = 0,