diff --git a/client/cmdflashmem.c b/client/cmdflashmem.c
index b77161951..3a744a544 100644
--- a/client/cmdflashmem.c
+++ b/client/cmdflashmem.c
@@ -351,8 +351,8 @@ static int CmdFlashMemSave(const char *Cmd) {
         return 1;
     }
 
-    saveFile(filename, "bin", dump, len);
-    saveFileEML(filename, "eml", dump, len, 16);
+    saveFile(filename, ".bin", dump, len);
+    saveFileEML(filename, dump, len, 16);
     free(dump);
     return 0;
 }
diff --git a/client/cmdhf14b.c b/client/cmdhf14b.c
index b1aa78e64..8f222b1e8 100644
--- a/client/cmdhf14b.c
+++ b/client/cmdhf14b.c
@@ -985,8 +985,8 @@ static int CmdHF14BDump(const char *Cmd) {
 
 
     size_t datalen = (blocks + 1) * 4;
-    saveFileEML(filename, "eml", data, datalen, 4);
-    saveFile(filename, "bin", data, datalen);
+    saveFileEML(filename, data, datalen, 4);
+    saveFile(filename, ".bin", data, datalen);
 out:
     return switch_off_field_14b();
 }
diff --git a/client/cmdhf15.c b/client/cmdhf15.c
index 496ea3073..db9f66735 100644
--- a/client/cmdhf15.c
+++ b/client/cmdhf15.c
@@ -842,8 +842,8 @@ static int CmdHF15Dump(const char *Cmd) {
     PrintAndLogEx(NORMAL, "\n");
 
     size_t datalen = blocknum * 4;
-    saveFileEML(filename, "eml", data, datalen, 4);
-    saveFile(filename, "bin", data, datalen);
+    saveFileEML(filename, data, datalen, 4);
+    saveFile(filename, ".bin", data, datalen);
     return 0;
 }
 
diff --git a/client/cmdhficlass.c b/client/cmdhficlass.c
index 5372022ab..b9a1b091d 100644
--- a/client/cmdhficlass.c
+++ b/client/cmdhficlass.c
@@ -425,7 +425,7 @@ static int CmdHFiClassSim(const char *Cmd) {
                 memcpy(dump + i * 24 + 16, resp.d.asBytes + i * 16 + 8, 8);
             }
             /** Now, save to dumpfile **/
-            saveFile("iclass_mac_attack", "bin", dump, datalen);
+            saveFile("iclass_mac_attack", ".bin", dump, datalen);
             free(dump);
             break;
         }
@@ -479,7 +479,7 @@ static int CmdHFiClassSim(const char *Cmd) {
                 // copy NR_MAC (eight bytes from the response)  ( 8b csn + 8b epurse == 16)
                 memcpy(dump + i * MAC_ITEM_SIZE + 16, resp.d.asBytes + i * 16 + 8, 8);
             }
-            saveFile("iclass_mac_attack_keyroll_A", "bin", dump, datalen);
+            saveFile("iclass_mac_attack_keyroll_A", ".bin", dump, datalen);
 
             //KEYROLL 2
             memset(dump, 0, datalen);
@@ -494,7 +494,7 @@ static int CmdHFiClassSim(const char *Cmd) {
                 memcpy(dump + i * MAC_ITEM_SIZE + 16, resp.d.asBytes + resp_index + 8, 8);
                 resp_index++;
             }
-            saveFile("iclass_mac_attack_keyroll_B", "bin", dump, datalen);
+            saveFile("iclass_mac_attack_keyroll_B", ".bin", dump, datalen);
             free(dump);
             break;
         }
@@ -720,7 +720,7 @@ static int CmdHFiClassDecrypt(const char *Cmd) {
         }
     }
 
-    saveFile(outfilename, "bin", decrypted, fsize);
+    saveFile(outfilename, ".bin", decrypted, fsize);
     printIclassDumpContents(decrypted, 1, (fsize / 8), fsize);
     free(decrypted);
     return 0;
@@ -1087,7 +1087,7 @@ static int CmdHFiClassReader_Dump(const char *Cmd) {
 
     // save the dump to .bin file
     PrintAndLogEx(SUCCESS, "saving dump file - %d blocks read", gotBytes / 8);
-    saveFile(filename, "bin", tag_data, gotBytes);
+    saveFile(filename, ".bin", tag_data, gotBytes);
     return 1;
 }
 
diff --git a/client/cmdhflegic.c b/client/cmdhflegic.c
index 0da3daaaa..3ea33f089 100644
--- a/client/cmdhflegic.c
+++ b/client/cmdhflegic.c
@@ -1212,8 +1212,8 @@ static int CmdLegicESave(const char *Cmd) {
     else
         sprintf(fnameptr + fileNlen, ".bin");
 
-    saveFileEML(filename, "eml", data, numofbytes, 8);
-    saveFile(filename, "bin", data, numofbytes);
+    saveFileEML(filename, data, numofbytes, 8);
+    saveFile(filename, ".bin", data, numofbytes);
     return 0;
 }
 
diff --git a/client/cmdhfmf.c b/client/cmdhfmf.c
index db1b7d798..120240e3e 100644
--- a/client/cmdhfmf.c
+++ b/client/cmdhfmf.c
@@ -917,9 +917,9 @@ static int CmdHF14AMfDump(const char *Cmd) {
 
     uint16_t bytes = 16 * (FirstBlockOfSector(numSectors - 1) + NumBlocksPerSector(numSectors - 1));
 
-    saveFile(dataFilename, "bin", (uint8_t *)carddata, bytes);
-    saveFileEML(dataFilename, "eml", (uint8_t *)carddata, bytes, MFBLOCK_SIZE);
-    saveFileJSON(dataFilename, "json", jsfCardMemory, (uint8_t *)carddata, bytes);
+    saveFile(dataFilename, ".bin", (uint8_t *)carddata, bytes);
+    saveFileEML(dataFilename, (uint8_t *)carddata, bytes, MFBLOCK_SIZE);
+    saveFileJSON(dataFilename, jsfCardMemory, (uint8_t *)carddata, bytes);
     return 0;
 }
 
@@ -2685,9 +2685,9 @@ static int CmdHF14AMfESave(const char *Cmd) {
         FillFileNameByUID(fnameptr, dump, "-dump", 4);
     }
 
-    saveFile(filename, "bin", dump, bytes);
-    saveFileEML(filename, "eml", dump, bytes, MFBLOCK_SIZE);
-    saveFileJSON(filename, "json", jsfCardMemory, dump, bytes);
+    saveFile(filename, ".bin", dump, bytes);
+    saveFileEML(filename, dump, bytes, MFBLOCK_SIZE);
+    saveFileJSON(filename, jsfCardMemory, dump, bytes);
     free(dump);
     return 0;
 }
@@ -3119,9 +3119,9 @@ static int CmdHF14AMfCSave(const char *Cmd) {
         PrintAndLogEx(SUCCESS, "uploaded %d bytes to emulator memory", bytes);
     }
 
-    saveFile(filename, "bin", dump, bytes);
-    saveFileEML(filename, "eml", dump, bytes, MFBLOCK_SIZE);
-    saveFileJSON(filename, "json", jsfCardMemory, dump, bytes);
+    saveFile(filename, ".bin", dump, bytes);
+    saveFileEML(filename, dump, bytes, MFBLOCK_SIZE);
+    saveFileJSON(filename, jsfCardMemory, dump, bytes);
     free(dump);
     return 0;
 }
diff --git a/client/cmdhfmfu.c b/client/cmdhfmfu.c
index 39ee6a6b0..501bd9551 100644
--- a/client/cmdhfmfu.c
+++ b/client/cmdhfmfu.c
@@ -1974,8 +1974,8 @@ static int CmdHF14AMfUDump(const char *Cmd) {
         FillFileNameByUID(fptr, card.uid, "-dump", card.uidlen);
     }
     uint16_t datalen = pages * 4 + MFU_DUMP_PREFIX_LENGTH;
-    saveFile(filename, "bin", (uint8_t *)&dump_file_data, datalen);
-    saveFileJSON(filename, "json", jsfMfuMemory, (uint8_t *)&dump_file_data, datalen);
+    saveFile(filename, ".bin", (uint8_t *)&dump_file_data, datalen);
+    saveFileJSON(filename, jsfMfuMemory, (uint8_t *)&dump_file_data, datalen);
 
     if (is_partial)
         PrintAndLogEx(WARNING, "Partial dump created. (%d of %d blocks)", pages, card_mem_size);
diff --git a/client/cmdlfhitag.c b/client/cmdlfhitag.c
index f901a042c..be66b460b 100644
--- a/client/cmdlfhitag.c
+++ b/client/cmdlfhitag.c
@@ -583,9 +583,9 @@ static int CmdLFHitagReader(const char *Cmd) {
         fnameptr += sprintf(fnameptr, "lf-hitag-");
         FillFileNameByUID(fnameptr, data, "-dump", 4);
 
-        saveFile(filename, "bin", data, 48);
-        saveFileEML(filename, "eml", data, 48, 4);
-        saveFileJSON(filename, "json", jsfHitag, data, 48);
+        saveFile(filename, ".bin", data, 48);
+        saveFileEML(filename, data, 48, 4);
+        saveFileJSON(filename, jsfHitag, data, 48);
 
         // block3, 1 byte
         printHitagConfiguration(data[4 * 3]);
diff --git a/client/cmdtrace.c b/client/cmdtrace.c
index 28605c08f..1582f2997 100644
--- a/client/cmdtrace.c
+++ b/client/cmdtrace.c
@@ -563,7 +563,7 @@ static int CmdTraceSave(const char *Cmd) {
     if (strlen(Cmd) < 1 || cmdp == 'h') return usage_trace_save();
 
     param_getstr(Cmd, 0, filename, sizeof(filename));
-    saveFile(filename, "bin", trace, traceLen);
+    saveFile(filename, ".bin", trace, traceLen);
     return 0;
 }
 
diff --git a/client/loclass/fileutils.c b/client/loclass/fileutils.c
index 5370c0c5b..5e3b423f7 100644
--- a/client/loclass/fileutils.c
+++ b/client/loclass/fileutils.c
@@ -57,15 +57,49 @@ int fileExists(const char *filename) {
     return result == 0;
 }
 
-int saveFile(const char *preferredName, const char *suffix, const void *data, size_t datalen) {
-    int size = sizeof(char) * (strlen(preferredName) + strlen(suffix) + 10);
-    char *fileName = calloc(size, sizeof(char));
+static char *filenamemcopy(const char *preferredName, const char *suffix) {
+    if (preferredName == NULL) return NULL;
+    if (suffix == NULL) return NULL;
+    char *fileName = (char *) calloc(strlen(preferredName) + strlen(suffix) + 1, sizeof(uint8_t));
+    if (fileName == NULL)
+        return NULL;
+    strcpy(fileName, preferredName);
+    if (str_endswith(fileName, suffix))
+        return fileName;
+    strcat(fileName, suffix);
+    return fileName;
+}
+
+static char *newfilenamemcopy(const char *preferredName, const char *suffix) {
+    if (preferredName == NULL) return NULL;
+    if (suffix == NULL) return NULL;
+    char *preferredNameTmp = (char *) calloc(strlen(preferredName) + 1, sizeof(uint8_t));
+    if (preferredNameTmp == NULL)
+        return NULL;
+    strcpy(preferredNameTmp, preferredName);
+    if (str_endswith(preferredNameTmp, suffix))
+        preferredNameTmp[strlen(preferredNameTmp) - strlen(suffix)] = '\0';
+    char *fileName = (char *) calloc(strlen(preferredNameTmp) + strlen(suffix) + 1 + 10, sizeof(uint8_t)); // 10: room for filenum to ensure new filename
+    if (fileName == NULL) {
+        free(preferredNameTmp);
+        return NULL;
+    }
     int num = 1;
-    sprintf(fileName, "%s.%s", preferredName, suffix);
+    sprintf(fileName, "%s%s", preferredNameTmp, suffix);
     while (fileExists(fileName)) {
-        sprintf(fileName, "%s-%d.%s", preferredName, num, suffix);
+        sprintf(fileName, "%s-%d%s", preferredNameTmp, num, suffix);
         num++;
     }
+    free(preferredNameTmp);
+    return fileName;
+}
+
+int saveFile(const char *preferredName, const char *suffix, const void *data, size_t datalen) {
+
+    if (data == NULL) return 1;
+    char *fileName = newfilenamemcopy(preferredName, suffix);
+    if (fileName == NULL) return 1;
+
     /* We should have a valid filename now, e.g. dumpdata-3.bin */
 
     /*Opening file for writing in binary mode*/
@@ -83,23 +117,15 @@ int saveFile(const char *preferredName, const char *suffix, const void *data, si
     return 0;
 }
 
-int saveFileEML(const char *preferredName, const char *suffix, uint8_t *data, size_t datalen, size_t blocksize) {
+int saveFileEML(const char *preferredName, uint8_t *data, size_t datalen, size_t blocksize) {
 
-    if (preferredName == NULL) return 1;
-    if (suffix == NULL) return 1;
     if (data == NULL) return 1;
+    char *fileName = newfilenamemcopy(preferredName, ".eml");
+    if (fileName == NULL) return 1;
 
     int retval = 0;
     int blocks = datalen / blocksize;
     uint16_t currblock = 1;
-    int size = sizeof(char) * (strlen(preferredName) + strlen(suffix) + 10);
-    char *fileName = calloc(size, sizeof(char));
-    int num = 1;
-    sprintf(fileName, "%s.%s", preferredName, suffix);
-    while (fileExists(fileName)) {
-        sprintf(fileName, "%s-%d.%s", preferredName, num, suffix);
-        num++;
-    }
 
     /* We should have a valid filename now, e.g. dumpdata-3.bin */
 
@@ -136,20 +162,13 @@ out:
     return retval;
 }
 
-int saveFileJSON(const char *preferredName, const char *suffix, JSONFileType ftype, uint8_t *data, size_t datalen) {
-    if (preferredName == NULL) return 1;
-    if (suffix == NULL) return 1;
+int saveFileJSON(const char *preferredName, JSONFileType ftype, uint8_t *data, size_t datalen) {
+
     if (data == NULL) return 1;
+    char *fileName = newfilenamemcopy(preferredName, ".json");
+    if (fileName == NULL) return 1;
 
     int retval = 0;
-    int size = sizeof(char) * (strlen(preferredName) + strlen(suffix) + 10);
-    char *fileName = calloc(size, sizeof(char));
-    int num = 1;
-    sprintf(fileName, "%s.%s", preferredName, suffix);
-    while (fileExists(fileName)) {
-        sprintf(fileName, "%s-%d.%s", preferredName, num, suffix);
-        num++;
-    }
 
     json_t *root = json_object();
     JsonSaveStr(root, "Created", "proxmark3");
diff --git a/client/loclass/fileutils.h b/client/loclass/fileutils.h
index 6f6b5456a..dae23a1b1 100644
--- a/client/loclass/fileutils.h
+++ b/client/loclass/fileutils.h
@@ -70,7 +70,7 @@ int fileExists(const char *filename);
  * E.g. dumpdata-15.txt
  *
  * @param preferredName
- * @param suffix the file suffix. Leave out the ".".
+ * @param suffix the file suffix. Including the ".".
  * @param data The binary data to write to the file
  * @param datalen the length of the data
  * @return 0 for ok, 1 for failz
@@ -83,13 +83,12 @@ int saveFile(const char *preferredName, const char *suffix, const void *data, si
  * E.g. dumpdata-15.txt
  *
  * @param preferredName
- * @param suffix the file suffix. Leave out the ".".
  * @param data The binary data to write to the file
  * @param datalen the length of the data
  * @param blocksize the length of one row
  * @return 0 for ok, 1 for failz
 */
-int saveFileEML(const char *preferredName, const char *suffix, uint8_t *data, size_t datalen, size_t blocksize);
+int saveFileEML(const char *preferredName, uint8_t *data, size_t datalen, size_t blocksize);
 
 /** STUB
  * @brief Utility function to save JSON data to a file. This method takes a preferred name, but if that
@@ -97,13 +96,12 @@ int saveFileEML(const char *preferredName, const char *suffix, uint8_t *data, si
  * E.g. dumpdata-15.json
  *
  * @param preferredName
- * @param suffix the file suffix. Leave out the ".".
  * @param ftype type of file.
  * @param data The binary data to write to the file
  * @param datalen the length of the data
  * @return 0 for ok, 1 for failz
  */
-int saveFileJSON(const char *preferredName, const char *suffix, JSONFileType ftype, uint8_t *data, size_t datalen);
+int saveFileJSON(const char *preferredName, JSONFileType ftype, uint8_t *data, size_t datalen);
 
 /** STUB
  * @brief Utility function to load data from a binary file. This method takes a preferred name.
diff --git a/client/util.c b/client/util.c
index 0d8781619..c215e05dd 100644
--- a/client/util.c
+++ b/client/util.c
@@ -938,16 +938,3 @@ char *strmcopy(const char *buf) {
     }
     return str;
 }
-
-char *filenamemcopy(const char *preferredName, const char *suffix) {
-    if (preferredName == NULL) return NULL;
-    if (suffix == NULL) return NULL;
-    char *fileName = (char *) calloc(strlen(preferredName) + strlen(suffix) + 1, sizeof(uint8_t));
-    if (fileName == NULL)
-        return NULL;
-    strcpy(fileName, preferredName);
-    if (str_endswith(fileName, suffix))
-        return fileName;
-    strcat(fileName, suffix);
-    return fileName;
-}
diff --git a/client/util.h b/client/util.h
index 6d0cc98aa..9674bd460 100644
--- a/client/util.h
+++ b/client/util.h
@@ -266,5 +266,4 @@ void clean_ascii(unsigned char *buf, size_t len);
 void strcleanrn(char *buf, size_t len);
 void strcreplace(char *buf, size_t len, char from, char to);
 char *strmcopy(const char *buf);
-char *filenamemcopy(const char *preferredName, const char *suffix);
 #endif