diff --git a/corec/corec/portab.h b/corec/corec/portab.h
index df423532..38c16b24 100644
--- a/corec/corec/portab.h
+++ b/corec/corec/portab.h
@@ -330,10 +330,6 @@ typedef uint64_t uint_fast64_t;
 #define TPRIx64  PRIx64
 #endif
 
-#define MAX_INT64 LL(0x7fffffffffffffff)
-
-#define MAX_TICK INT_MAX
-
 typedef int_fast32_t err_t;
 typedef int_fast32_t bool_t;
 typedef int_fast32_t tick_t;
@@ -498,10 +494,10 @@ void * __alloca(size_t size);
 
 #ifdef CONFIG_FILEPOS_64
 typedef int_fast64_t filepos_t;
-#define MAX_FILEPOS MAX_INT64
+#define MAX_FILEPOS INT_FAST64_MAX
 #else
 typedef int_fast32_t filepos_t;
-#define MAX_FILEPOS INT_MAX
+#define MAX_FILEPOS INT_FAST32_MAX
 #endif
 
 #define INVALID_FILEPOS_T  ((filepos_t)-1)
diff --git a/corec/corec/str/str.c b/corec/corec/str/str.c
index 6f1a3efa..1760d5da 100644
--- a/corec/corec/str/str.c
+++ b/corec/corec/str/str.c
@@ -185,7 +185,7 @@ static int get_integers(int64_t IntValue)
 {
     int Result = 0;
     int64_t TmpVal = 1;
-    while (IntValue >= TmpVal && TmpVal < MAX_INT64/10)
+    while (IntValue >= TmpVal && TmpVal < INT64_MAX/10)
     {
         TmpVal *= 10;
         Result++;
@@ -197,7 +197,7 @@ static int get_decimals(int Decimals, int64_t IntValue)
 {
     int Result = 0;
     int64_t TmpVal = IntValue+1;
-    while (TmpVal < MAX_INT64/10)
+    while (TmpVal < INT64_MAX/10)
     {
         TmpVal *= 10;
         Result++;
diff --git a/libmatroska2/matroska2/matroska.h b/libmatroska2/matroska2/matroska.h
index f7eb9c14..6fae6557 100644
--- a/libmatroska2/matroska2/matroska.h
+++ b/libmatroska2/matroska2/matroska.h
@@ -58,7 +58,7 @@
 
 MATROSKA_DLL err_t MATROSKA_Init(parsercontext *p);
 
-#define INVALID_TIMESTAMP_T      MAX_INT64
+#define INVALID_TIMESTAMP_T      INT64_MAX
 typedef int64_t    mkv_timestamp_t; // in nanoseconds
 
 typedef struct matroska_block matroska_block;