diff --git a/runtime/compiletime/instr.c b/runtime/compiletime/instr.c
index 4c87f21..7ed486a 100644
--- a/runtime/compiletime/instr.c
+++ b/runtime/compiletime/instr.c
@@ -94,15 +94,15 @@ u64_rem(uint64_t a, uint64_t b)
 	return a % b;
 }
 
-INLINE i64
-i64_div(i64 a, i64 b)
+INLINE int64_t
+i64_div(int64_t a, int64_t b)
 {
 	assert(b && (a != INT64_MIN || b != -1));
 	return a / b;
 }
 
-INLINE i64
-i64_rem(i64 a, i64 b)
+INLINE int64_t
+i64_rem(int64_t a, int64_t b)
 {
 	assert(b && (a != INT64_MIN || b != -1));
 	return a % b;
@@ -146,11 +146,11 @@ u64_trunc_f32(float f)
 	return (uint64_t)f;
 }
 
-i64
+int64_t
 i64_trunc_f32(float f)
 {
 	assert(INT64_MIN <= f && f <= INT64_MAX);
-	return (i64)f;
+	return (int64_t)f;
 }
 
 uint64_t
@@ -160,11 +160,11 @@ u64_trunc_f64(double f)
 	return (uint64_t)f;
 }
 
-i64
+int64_t
 i64_trunc_f64(double f)
 {
 	assert(INT64_MIN <= f && f <= INT64_MAX);
-	return (i64)f;
+	return (int64_t)f;
 }
 
 // Float => Float truncation functions
diff --git a/runtime/compiletime/memory/64bit_nix.c b/runtime/compiletime/memory/64bit_nix.c
index 75e12f9..3a4e5ca 100644
--- a/runtime/compiletime/memory/64bit_nix.c
+++ b/runtime/compiletime/memory/64bit_nix.c
@@ -49,13 +49,13 @@ get_i32(i32 offset)
 	return *(i32 *)address;
 }
 
-INLINE i64
+INLINE int64_t
 get_i64(i32 offset)
 {
 	char *mem_as_chars = (char *)local_sandbox_context_cache.linear_memory_start;
 	void *address      = &mem_as_chars[offset];
 
-	return *(i64 *)address;
+	return *(int64_t *)address;
 }
 
 INLINE i32
@@ -67,13 +67,13 @@ get_global_i32(i32 offset)
 	return *(i32 *)address;
 }
 
-INLINE i64
+INLINE int64_t
 get_global_i64(i32 offset)
 {
 	char *mem_as_chars = (char *)local_sandbox_context_cache.linear_memory_start;
 	void *address      = &mem_as_chars[offset];
 
-	return *(i64 *)address;
+	return *(int64_t *)address;
 }
 
 // Now setting routines
@@ -123,12 +123,12 @@ set_i32(i32 offset, i32 v)
 }
 
 INLINE void
-set_i64(i32 offset, i64 v)
+set_i64(i32 offset, int64_t v)
 {
 	char *mem_as_chars = (char *)local_sandbox_context_cache.linear_memory_start;
 	void *address      = &mem_as_chars[offset];
 
-	*(i64 *)address = v;
+	*(int64_t *)address = v;
 }
 
 INLINE void
@@ -141,12 +141,12 @@ set_global_i32(i32 offset, i32 v)
 }
 
 INLINE void
-set_global_i64(i32 offset, i64 v)
+set_global_i64(i32 offset, int64_t v)
 {
 	char *mem_as_chars = (char *)local_sandbox_context_cache.linear_memory_start;
 	void *address      = &mem_as_chars[offset];
 
-	*(i64 *)address = v;
+	*(int64_t *)address = v;
 }
 
 // Table handling functionality
diff --git a/runtime/include/types.h b/runtime/include/types.h
index 2a97401..6412d11 100644
--- a/runtime/include/types.h
+++ b/runtime/include/types.h
@@ -41,7 +41,6 @@ typedef unsigned char u8;
 typedef int16_t       i16;
 typedef uint16_t      u16;
 typedef int32_t       i32;
-typedef int64_t       i64;
 
 /* FIXME: per-module configuration? */
 #define WASM_PAGE_SIZE   (1024 * 64) /* 64KB */
diff --git a/runtime/src/env.c b/runtime/src/env.c
index 02bcb9b..f262795 100644
--- a/runtime/src/env.c
+++ b/runtime/src/env.c
@@ -40,10 +40,10 @@ env_a_and_64(i32 p_off, uint64_t v)
 }
 
 INLINE void
-env_a_or_64(i32 p_off, i64 v)
+env_a_or_64(i32 p_off, int64_t v)
 {
-	assert(sizeof(i64) == sizeof(uint64_t));
-	uint64_t *p = worker_thread_get_memory_ptr_void(p_off, sizeof(i64));
+	assert(sizeof(int64_t) == sizeof(uint64_t));
+	uint64_t *p = worker_thread_get_memory_ptr_void(p_off, sizeof(int64_t));
 	ck_pr_or_64(p, v);
 }
 
diff --git a/runtime/src/libc/uvio.c b/runtime/src/libc/uvio.c
index 13ccaf2..441c1f4 100644
--- a/runtime/src/libc/uvio.c
+++ b/runtime/src/libc/uvio.c
@@ -249,7 +249,7 @@ wasm_close(i32 file_descriptor)
 
 // What the wasm stat structure looks like
 struct wasm_stat {
-	i64      st_dev;
+	int64_t  st_dev;
 	uint64_t st_ino;
 	uint32_t st_nlink;
 
@@ -260,7 +260,7 @@ struct wasm_stat {
 	uint64_t st_rdev;
 	uint64_t st_size;
 	i32      st_blksize;
-	i64      st_blocks;
+	int64_t  st_blocks;
 
 	struct {
 		i32 tv_sec;