diff --git a/include/utils/utils.h b/include/utils/utils.h
index 354147f..5ee309f 100644
--- a/include/utils/utils.h
+++ b/include/utils/utils.h
@@ -119,9 +119,23 @@ extern "C" {
 #define __packed        __attribute__((__packed__))
 #endif
 
+#ifdef __GNUC__
+#define PACK( __Declaration__ ) __Declaration__ __attribute__((__packed__))
+#endif
+
+#ifdef _MSC_VER
+#define PACK( __Declaration__ ) __pragma( pack(push, 1) ) __Declaration__ __pragma( pack(pop))
+#endif
+
 #undef __weak
 #define __weak          __attribute__((weak))
 
+#if (defined(_WIN32) || defined(_WIN64))
+#define __format_printf(x, y)
+#else
+#define __format_printf(x, y) __attribute__((format(printf, x, y)))
+#endif
+
 /**
  * @brief Return random number between 0 and `limit` both inclusive.
  *
@@ -193,7 +207,7 @@ void dump_trace(void);
 
 static inline bool char_is_space(int c)
 {
-	unsigned char d = c - 9;
+	unsigned char d = (unsigned char)(c - 9);
 	return (0x80001FU >> (d & 31)) & (1U >> (d >> 5));
 }
 
diff --git a/src/disjoint_set.c b/src/disjoint_set.c
index f5dabf8..08c7d0e 100644
--- a/src/disjoint_set.c
+++ b/src/disjoint_set.c
@@ -49,8 +49,12 @@ void disjoint_set_union(struct disjoint_set *set, int a, int b)
 	if (a == b)
 		return;
 
-	if (set->rank[a] < set->rank[b])
-		SWAP(a, b);
+	if (set->rank[a] < set->rank[b]) {
+		int tmp;
+		tmp = a;
+		a = b;
+		b = tmp;
+	}
 
 	set->parent[b] = a;
 	if (set->rank[a] == set->rank[b])
diff --git a/src/logger.c b/src/logger.c
index 0f53f25..2e9a48a 100644
--- a/src/logger.c
+++ b/src/logger.c
@@ -6,10 +6,12 @@
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <unistd.h>
 #include <string.h>
 #include <assert.h>
 #include <time.h>
+#if (!defined(_WIN32) && !defined(_WIN64))
+#include <unistd.h>
+#endif
 
 #include <utils/logger.h>
 
@@ -98,7 +100,7 @@ static int terminate_log_line(char *buf, int len)
 
 #define LOG_BUF_LEN 192
 
-__attribute__((format(printf, 5, 6)))
+__format_printf(5, 6)
 int __logger_log(logger_t *ctx, int log_level, const char *file, unsigned long line,
 		 const char *fmt, ...)
 {
diff --git a/src/slab.c b/src/slab.c
index 0a621b8..c8d86e4 100644
--- a/src/slab.c
+++ b/src/slab.c
@@ -10,11 +10,11 @@
 
 #include <utils/slab.h>
 
-struct slab_unit {
+PACK(struct slab_unit {
 	uint32_t leased;
 	uint32_t canary;
 	uint8_t data[];
-} __packed;
+});
 
 int slab_init(slab_t *slab, size_t slab_size,
 	      uint8_t *blob, size_t blob_size)
diff --git a/src/utils.c b/src/utils.c
index 01a4ac6..72e3147 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -9,8 +9,6 @@
 #include <stddef.h>
 #include <ctype.h>
 #include <stdlib.h>
-#include <time.h>
-#include <sys/time.h>
 
 #include <utils/utils.h>
 
@@ -49,7 +47,7 @@ int num_digits_in_number(int num)
 	return digits;
 }
 
-__attribute__((format(printf, 3, 4)))
+__format_printf(3, 4)
 void hexdump(const void *p, size_t len, const char *fmt, ...)
 {
 	size_t i;
@@ -87,6 +85,43 @@ void hexdump(const void *p, size_t len, const char *fmt, ...)
 	printf("\n");
 }
 
+#if (defined(_WIN32) || defined(_WIN64))
+#define WIN32_LEAN_AND_MEAN
+#include <Windows.h>
+#include <stdint.h> // portable: uint64_t   MSVC: __int64
+
+// MSVC defines this in winsock2.h!?
+typedef struct timeval {
+	long tv_sec;
+	long tv_usec;
+} timeval;
+
+int gettimeofday(struct timeval * tp, struct timezone * tzp)
+{
+	// Note: some broken versions only have 8 trailing zero's, the correct
+	// epoch has 9 trailing zero's This magic number is the number of 100
+	// nanosecond intervals since January 1, 1601 (UTC) until 00:00:00
+	// January 1, 1970
+	static const uint64_t EPOCH = ((uint64_t) 116444736000000000ULL);
+
+	SYSTEMTIME  system_time;
+	FILETIME    file_time;
+	uint64_t    time;
+
+	GetSystemTime( &system_time );
+	SystemTimeToFileTime( &system_time, &file_time );
+	time =  ((uint64_t)file_time.dwLowDateTime )      ;
+	time += ((uint64_t)file_time.dwHighDateTime) << 32;
+
+	tp->tv_sec  = (long) ((time - EPOCH) / 10000000L);
+	tp->tv_usec = (long) (system_time.wMilliseconds * 1000);
+	return 0;
+}
+#else
+#include <sys/time.h>
+#include <time.h>
+#endif
+
 int64_t usec_now()
 {
 	int64_t usec;