diff --git a/include/aaruformat/context.h b/include/aaruformat/context.h
index b7471c2..6336446 100644
--- a/include/aaruformat/context.h
+++ b/include/aaruformat/context.h
@@ -140,7 +140,7 @@ typedef struct TapePartitionHashEntry
 typedef struct TapeDdtHashEntry
 {
     uint64_t       key;    ///< Key: sector address
-    uint32_t       value;  ///< Value: DDT entry
+    uint64_t       value;  ///< Value: DDT entry
     UT_hash_handle hh;     ///< UTHASH handle
 } TapeDdtHashEntry;
 
diff --git a/src/close.c b/src/close.c
index b3896e9..be4c208 100644
--- a/src/close.c
+++ b/src/close.c
@@ -124,7 +124,7 @@ static int32_t write_cached_secondary_ddt(aaruformat_context *ctx)
     ddt_header.start             = ctx->cached_ddt_position * items_per_ddt_entry;
 
     // Calculate data size
-    ddt_header.length = items_per_ddt_entry * sizeof(uint32_t);
+    ddt_header.length = items_per_ddt_entry * sizeof(uint64_t);
 
     // Calculate CRC64 of the data
     crc64_ctx *crc64_context = aaruf_crc64_init();
@@ -230,7 +230,7 @@ static int32_t write_cached_secondary_ddt(aaruformat_context *ctx)
             long saved_pos = ftell(ctx->imageStream);
             fseek(ctx->imageStream, ctx->primary_ddt_offset + sizeof(DdtHeader2), SEEK_SET);
 
-            size_t primary_table_size = ctx->user_data_ddt_header.entries * sizeof(uint32_t);
+            size_t primary_table_size = ctx->user_data_ddt_header.entries * sizeof(uint64_t);
 
             size_t primary_written_bytes = 0;
             primary_written_bytes        = fwrite(ctx->user_data_ddt2, primary_table_size, 1, ctx->imageStream);
@@ -322,7 +322,7 @@ static int32_t write_primary_ddt(aaruformat_context *ctx)
     }
 
     // Then write the table data (position is already after the header)
-    size_t primary_table_size = ctx->user_data_ddt_header.entries * sizeof(uint32_t);
+    size_t primary_table_size = ctx->user_data_ddt_header.entries * sizeof(uint64_t);
 
     // Write the primary table data
     size_t written_bytes = 0;
diff --git a/src/create.c b/src/create.c
index 58449b6..f73b702 100644
--- a/src/create.c
+++ b/src/create.c
@@ -519,7 +519,7 @@ void *aaruf_create(const char *filepath, const uint32_t media_type, const uint32
         TRACE("Primary DDT will be placed at offset %" PRIu64, ctx->primary_ddt_offset);
 
         // Calculate size of primary DDT table
-        const uint64_t primary_table_size = ctx->user_data_ddt_header.entries * sizeof(uint32_t);
+        const uint64_t primary_table_size = ctx->user_data_ddt_header.entries * sizeof(uint64_t);
 
         // Calculate where data blocks can start (after primary DDT + header)
         if(ctx->user_data_ddt_header.tableShift > 0)