diff --git a/libs/libc/stdio/lib_fopen.c b/libs/libc/stdio/lib_fopen.c
index 160c3e764a9..40df4882c1c 100644
--- a/libs/libc/stdio/lib_fopen.c
+++ b/libs/libc/stdio/lib_fopen.c
@@ -45,11 +45,6 @@
                             * or creating file */
 #define MODE_A    (1 << 2) /* Bit 2: "a{b|x|+}" open for writing, appending
                             * the to file */
-#define MODE_PLUS (1 << 3) /* Bit 3: "{r|w|a|b|x}+" open for update (reading
-                            * and writing) */
-#define MODE_B    (1 << 4) /* Bit 4: "{r|w|a|x|+}b" Binary mode */
-#define MODE_X    (1 << 5) /* Bit 5: "{r|w|a|b|+}x" Open exclusive mode */
-#define MODE_T    (1 << 6) /* Bit 6: "{r|w|a|+}t" Text mode */
 
 #define MODE_NONE 0        /* No access mode determined */
 #define MODE_MASK (MODE_R | MODE_W | MODE_A)
@@ -214,7 +209,6 @@ int lib_mode2oflags(FAR const char *mode)
                     /* Open for read/write access */
 
                     oflags |= O_RDWR;
-                    state  |= MODE_PLUS;
                  }
                  break;
 
@@ -229,7 +223,6 @@ int lib_mode2oflags(FAR const char *mode)
                      */
 
                     oflags |= (O_RDWR | O_CREAT | O_TRUNC);
-                    state  |= MODE_PLUS;
                   }
                   break;
 
@@ -244,7 +237,6 @@ int lib_mode2oflags(FAR const char *mode)
                      */
 
                     oflags |= (O_RDWR | O_CREAT | O_APPEND);
-                    state  |= MODE_PLUS;
                   }
                   break;
 
@@ -262,7 +254,6 @@ int lib_mode2oflags(FAR const char *mode)
                 /* The file is opened in binary mode */
 
                 oflags |= O_BINARY;
-                state  |= MODE_B;
               }
             else
               {
@@ -278,7 +269,6 @@ int lib_mode2oflags(FAR const char *mode)
                 /* The file is opened in exclusive mode */
 
                 oflags |= O_EXCL;
-                state  |= MODE_X;
               }
             else
               {
@@ -294,7 +284,6 @@ int lib_mode2oflags(FAR const char *mode)
                 /* The file is opened in text mode */
 
                 oflags |= O_TEXT;
-                state  |= MODE_T;
               }
             else
               {