diff --git a/src/tpm12/tpm_nvfile.c b/src/tpm12/tpm_nvfile.c
index c8e7bcf5..0268bd0c 100644
--- a/src/tpm12/tpm_nvfile.c
+++ b/src/tpm12/tpm_nvfile.c
@@ -70,7 +70,8 @@
 
 /* local prototypes */
 
-static void       TPM_NVRAM_GetFilenameForName(char *filename,
+static TPM_RESULT TPM_NVRAM_GetFilenameForName(char *filename,
+                                               size_t filename_len,
 					       uint32_t tpm_number,
                                                const char *name);
 
@@ -189,7 +190,10 @@ TPM_RESULT TPM_NVRAM_LoadData(unsigned char **data,     /* freed by caller */
     /* open the file */
     if (rc == 0) {
         /* map name to the rooted filename */
-        TPM_NVRAM_GetFilenameForName(filename, tpm_number, name);
+        rc = TPM_NVRAM_GetFilenameForName(filename, sizeof(filename),
+                                          tpm_number, name);
+    }
+    if (rc == 0) {
         printf("  TPM_NVRAM_LoadData: Opening file %s\n", filename);
         file = fopen(filename, "rb");                           /* closed @1 */
         if (file == NULL) {     /* if failure, determine cause */
@@ -297,7 +301,10 @@ TPM_RESULT TPM_NVRAM_StoreData(const unsigned char *data,
     printf(" TPM_NVRAM_StoreData: To name %s\n", name);
     if (rc == 0) {
         /* map name to the rooted filename */
-        TPM_NVRAM_GetFilenameForName(filename, tpm_number, name);
+        rc = TPM_NVRAM_GetFilenameForName(filename, sizeof(filename),
+                                          tpm_number, name);
+    }
+    if (rc == 0) {
         /* open the file */
         printf(" TPM_NVRAM_StoreData: Opening file %s\n", filename);
         file = fopen(filename, "wb");                           /* closed @1 */
@@ -339,14 +346,27 @@ TPM_RESULT TPM_NVRAM_StoreData(const unsigned char *data,
    state_directory/tpm_number.name
 */
 
-static void TPM_NVRAM_GetFilenameForName(char *filename,        /* output: rooted filename */
-					 uint32_t tpm_number,
-                                         const char *name)      /* input: abstract name */
+static TPM_RESULT TPM_NVRAM_GetFilenameForName(char *filename,        /* output: rooted filename */
+					       size_t filename_len,
+					       uint32_t tpm_number,
+                                               const char *name)      /* input: abstract name */
 {
+    int n;
+    TPM_RESULT rc = TPM_FAIL;
+
     printf(" TPM_NVRAM_GetFilenameForName: For name %s\n", name);
-    sprintf(filename, "%s/%02lx.%s", state_directory, (unsigned long)tpm_number, name);
-    printf("  TPM_NVRAM_GetFilenameForName: File name %s\n", filename);
-    return;
+    n = snprintf(filename, filename_len,
+                 "%s/%02lx.%s", state_directory, (unsigned long)tpm_number,
+                 name);
+    if (n < 0) {
+        printf(" TPM_NVRAM_GetFilenameForName: Error (fatal), snprintf failed\n");
+    } else if ((size_t)n >= filename_len) {
+        printf(" TPM_NVRAM_GetFilenameForName: Error (fatal), buffer too small\n");
+    } else {
+        printf("  TPM_NVRAM_GetFilenameForName: File name %s\n", filename);
+        rc = TPM_SUCCESS;
+    }
+    return rc;
 }
 
 /* TPM_NVRAM_DeleteName() deletes the 'name' from NVRAM
@@ -380,7 +400,10 @@ TPM_RESULT TPM_NVRAM_DeleteName(uint32_t tpm_number,
     
     printf(" TPM_NVRAM_DeleteName: Name %s\n", name);
     /* map name to the rooted filename */
-    TPM_NVRAM_GetFilenameForName(filename, tpm_number, name);
+    if (rc == 0) {
+        rc = TPM_NVRAM_GetFilenameForName(filename, sizeof(filename),
+                                          tpm_number, name);
+    }
     if (rc == 0) {
         irc = remove(filename);
         if ((irc != 0) &&               /* if the remove failed */