diff --git a/reactos/base/setup/usetup/interface/usetup.c b/reactos/base/setup/usetup/interface/usetup.c
index de945787332..8be6612e99f 100644
--- a/reactos/base/setup/usetup/interface/usetup.c
+++ b/reactos/base/setup/usetup/interface/usetup.c
@@ -2403,7 +2403,7 @@ DeletePartitionPage(PINPUT_RECORD Ir)
     ULONGLONG DiskSize;
     ULONGLONG PartSize;
     PCHAR Unit;
-    CHAR PartType[32];
+    CHAR PartTypeString[32];
 
     if (PartitionList == NULL ||
         PartitionList->CurrentDisk == NULL ||
@@ -2418,7 +2418,9 @@ DeletePartitionPage(PINPUT_RECORD Ir)
 
     MUIDisplayPage(DELETE_PARTITION_PAGE);
 
-    GetPartTypeStringFromPartitionType(PartEntry->PartitionType, PartType, 30);
+    GetPartTypeStringFromPartitionType(PartEntry->PartitionType,
+                                       PartTypeString,
+                                       ARRAYSIZE(PartTypeString));
 
     PartSize = PartEntry->SectorCount.QuadPart * DiskEntry->BytesPerSector;
 #if 0
@@ -2440,7 +2442,7 @@ DeletePartitionPage(PINPUT_RECORD Ir)
         Unit = MUIGetString(STRING_KB);
     }
 
-    if (PartType == NULL)
+    if (*PartTypeString == '\0') // STRING_FORMATUNKNOWN ??
     {
         CONSOLE_PrintTextXY(6, 10,
                             MUIGetString(STRING_HDDINFOUNK2),
@@ -2456,7 +2458,7 @@ DeletePartitionPage(PINPUT_RECORD Ir)
                             "   %c%c  %s    %I64u %s",
                             (PartEntry->DriveLetter == 0) ? '-' : PartEntry->DriveLetter,
                             (PartEntry->DriveLetter == 0) ? '-' : ':',
-                            PartType,
+                            PartTypeString,
                             PartSize,
                             Unit);
     }
@@ -2696,7 +2698,9 @@ SelectFileSystemPage(PINPUT_RECORD Ir)
     }
 
     /* adjust partition type */
-    GetPartTypeStringFromPartitionType(PartEntry->PartitionType, PartTypeString, 30);
+    GetPartTypeStringFromPartitionType(PartEntry->PartitionType,
+                                       PartTypeString,
+                                       ARRAYSIZE(PartTypeString));
 
     if (PartEntry->AutoCreate == TRUE)
     {
@@ -2707,7 +2711,7 @@ SelectFileSystemPage(PINPUT_RECORD Ir)
                             PartEntry->PartitionNumber,
                             PartSize,
                             PartUnit,
-                            PartType);
+                            PartTypeString);
 #endif
 
         CONSOLE_PrintTextXY(8, 10, MUIGetString(STRING_HDINFOPARTZEROED),
@@ -2750,7 +2754,7 @@ SelectFileSystemPage(PINPUT_RECORD Ir)
     {
         CONSOLE_SetTextXY(6, 8, MUIGetString(STRING_INSTALLONPART));
 
-        if (PartTypeString == NULL)
+        if (*PartTypeString == '\0') // STRING_FORMATUNKNOWN ??
         {
             CONSOLE_PrintTextXY(8, 10,
                                 MUIGetString(STRING_HDDINFOUNK4),
diff --git a/reactos/base/setup/usetup/partlist.c b/reactos/base/setup/usetup/partlist.c
index 88ae8996c52..cec59c1beee 100644
--- a/reactos/base/setup/usetup/partlist.c
+++ b/reactos/base/setup/usetup/partlist.c
@@ -1672,7 +1672,7 @@ PrintPartitionData(
         {
            GetPartTypeStringFromPartitionType(PartEntry->PartitionType,
                                               PartTypeString,
-                                              30);
+                                              ARRAYSIZE(PartTypeString));
            PartType = PartTypeString;
         }