diff --git a/Libraries/LibC/bits/stdint.h b/Libraries/LibC/bits/stdint.h
index 8e1fbcba4d..4fc2865904 100644
--- a/Libraries/LibC/bits/stdint.h
+++ b/Libraries/LibC/bits/stdint.h
@@ -101,6 +101,15 @@ typedef __INTMAX_TYPE__ intmax_t;
 #define UINT_LEAST32_MAX UINT32_MAX
 #define UINT_LEAST64_MAX UINT64_MAX
 
+#define INT8_C(x) x
+#define UINT8_C(x) x
+
+#define INT16_C(x) x
+#define UINT16_C(x) x
+
+#define INT32_C(x) x
+#define UINT32_C(x) x
+
 #define INT64_C(x) x##LL
 #define UINT64_C(x) x##ULL
 
diff --git a/Libraries/LibC/inttypes.h b/Libraries/LibC/inttypes.h
index 7f27521caa..fb6b932765 100644
--- a/Libraries/LibC/inttypes.h
+++ b/Libraries/LibC/inttypes.h
@@ -17,7 +17,9 @@
 #define PRIx8 "b"
 #define PRIx16 "w"
 #define PRIx32 "x"
+#define PRIX32 "X"
 #define PRIx64 "llx"
+#define PRIX64 "llX"
 
 #define __PRI64_PREFIX "ll"
 #define __PRIPTR_PREFIX
diff --git a/Libraries/LibC/stdio.cpp b/Libraries/LibC/stdio.cpp
index ae9872c877..7a1cdc9069 100644
--- a/Libraries/LibC/stdio.cpp
+++ b/Libraries/LibC/stdio.cpp
@@ -437,7 +437,9 @@ void perror(const char* s)
 FILE* fopen(const char* pathname, const char* mode)
 {
     int flags = 0;
-    if (!strcmp(mode, "r") || !strcmp(mode, "rb"))
+    // NOTE: rt is a non-standard mode which opens a file for read, explicitly
+    // specifying that it's a text file
+    if (!strcmp(mode, "r") || !strcmp(mode, "rb") || !strcmp(mode, "rt"))
         flags = O_RDONLY;
     else if (!strcmp(mode, "r+") || !strcmp(mode, "rb+"))
         flags = O_RDWR;
diff --git a/Libraries/LibC/stdio.h b/Libraries/LibC/stdio.h
index 18214fb0e8..dd71933720 100644
--- a/Libraries/LibC/stdio.h
+++ b/Libraries/LibC/stdio.h
@@ -7,6 +7,7 @@
 #include <sys/cdefs.h>
 #include <sys/types.h>
 
+#define FILENAME_MAX 1024
 #define BUFSIZ 1024
 
 __BEGIN_DECLS
diff --git a/Libraries/LibC/time.cpp b/Libraries/LibC/time.cpp
index 8a301b3bb5..cdc48f0f08 100644
--- a/Libraries/LibC/time.cpp
+++ b/Libraries/LibC/time.cpp
@@ -4,6 +4,7 @@
 #include <sys/time.h>
 #include <sys/times.h>
 #include <time.h>
+#include <string.h>
 
 extern "C" {
 
@@ -96,9 +97,11 @@ char* asctime(const struct tm*)
     ASSERT_NOT_REACHED();
 }
 
-size_t strftime(char*, size_t, const char*, const struct tm*)
+size_t strftime(char* destination, size_t, const char*, const struct tm*)
 {
-    ASSERT_NOT_REACHED();
+    // FIXME: Stubbed function to make nasm work. Should be properly implemented
+    strcpy(destination, "strftime_unimplemented");
+    return strlen("strftime_unimplemented");
 }
 
 long timezone;