diff --git a/src/timer.c b/src/timer.c
index 67939ad..8e41f14 100644
--- a/src/timer.c
+++ b/src/timer.c
@@ -1,9 +1,10 @@
 #include <errno.h>
+#include <inttypes.h>
 #include "timer.h"
 
-#define GIGA 1e9
+#define GIGA 1000000000
 
-#if defined(__unix__)
+#if defined(__unix__) && !defined(__CYGWIN__)
 
 # ifdef CLOCK_MONOTONIC_RAW
 #  define CLOCK CLOCK_MONOTONIC_RAW
@@ -16,14 +17,14 @@ extern __attribute__ ((weak)) int clock_gettime(clockid_t, struct timespec *);
 #elif defined(__APPLE__)
 # include <mach/clock.h>
 # include <mach/mach.h>
-#elif defined(_WIN32)
+#elif defined(_WIN32) || defined(__CYGWIN__)
 # define VC_EXTRALEAN
 # define WIN32_LEAN_AND_MEAN
 # include <Windows.h>
 #endif
 
 bool can_measure_time(void) {
-#ifdef __unix__
+#if defined(__unix__) && !defined(__CYGWIN__)
     return clock_gettime != NULL;
 #else
     return true;
@@ -41,13 +42,16 @@ int gettime_compat(struct timespec_compat *ts) {
 
     *ts = (struct timespec_compat) { mts->tv_sec, mts->tv_nsec };
     return res > 0 ? -1 : 0;
-#elif defined(_WIN32)
+#elif defined(_WIN32) || defined(__CYGWIN__)
     LARGE_INTEGER freq, count;
     if (!QueryPerformanceFrequency(&freq)
         || !QueryPerformanceCounter(&count))
         return -1;
 
-    *ts = (struct timespec_compat) { count / freq, count * (GIGA - 1) / freq };
+    int64_t sec  = count.QuadPart / freq.QuadPart;
+    int64_t nano = (int64_t) ((double) count.QuadPart * GIGA / (double) freq.QuadPart) % GIGA;
+
+    *ts = (struct timespec_compat) { sec, nano };
     return 0;
 #elif defined(__unix__)
     if (!can_measure_time()) {
@@ -74,6 +78,6 @@ int timer_end(double *time, struct timespec_compat *state) {
     if (gettime_compat(&last) == -1)
         return 0;
 
-    *time = (last.tv_sec - state->tv_sec) + (last.tv_nsec - state->tv_nsec) / GIGA;
+    *time = (last.tv_sec - state->tv_sec) + (last.tv_nsec - state->tv_nsec) / (double) GIGA;
     return 1;
 }