diff --git a/dlls/quartz/tests/filtergraph.c b/dlls/quartz/tests/filtergraph.c
index 68b4863442f..f0aa084192d 100644
--- a/dlls/quartz/tests/filtergraph.c
+++ b/dlls/quartz/tests/filtergraph.c
@@ -41,6 +41,12 @@ typedef struct TestFilterImpl
     UINT nPins;
 } TestFilterImpl;
 
+static BOOL compare_time(ULONGLONG x, ULONGLONG y, unsigned int max_diff)
+{
+    ULONGLONG diff = x > y ? x - y : y - x;
+    return diff <= max_diff;
+}
+
 static WCHAR *create_file(const WCHAR *name, const char *data, DWORD size)
 {
     static WCHAR pathW[MAX_PATH];
@@ -4057,13 +4063,13 @@ static void test_graph_seeking(void)
     hr = IMediaSeeking_GetCurrentPosition(seeking, &time);
     ok(hr == S_OK, "Got hr %#x.\n", hr);
     if (winetest_interactive) /* Timing problems make this test too liable to fail. */
-        ok(abs(time - 1234 * 10000) < 40 * 10000,
+        ok(compare_time(time, 1234 * 10000, 40 * 10000),
                 "Expected about 1234ms, got %s.\n", wine_dbgstr_longlong(time));
     current = stop = 0xdeadbeef;
     hr = IMediaSeeking_GetPositions(seeking, &current, &stop);
     ok(hr == S_OK, "Got hr %#x.\n", hr);
     if (winetest_interactive) /* Timing problems make this test too liable to fail. */
-        ok(abs(current - 1234 * 10000) < 40 * 10000,
+        ok(compare_time(current, 1234 * 10000, 40 * 10000),
                 "Expected about 1234ms, got %s.\n", wine_dbgstr_longlong(current));
     ok(stop == 9000 * 10000, "Got time %s.\n", wine_dbgstr_longlong(stop));
 
@@ -4080,13 +4086,13 @@ static void test_graph_seeking(void)
     hr = IMediaSeeking_GetCurrentPosition(seeking, &time);
     ok(hr == S_OK, "Got hr %#x.\n", hr);
     if (winetest_interactive) /* Timing problems make this test too liable to fail. */
-        ok(abs(time - 1334 * 10000) < 80 * 10000,
+        ok(compare_time(time, 1334 * 10000, 80 * 10000),
                 "Expected about 1334ms, got %s.\n", wine_dbgstr_longlong(time));
     current = stop = 0xdeadbeef;
     hr = IMediaSeeking_GetPositions(seeking, &current, &stop);
     ok(hr == S_OK, "Got hr %#x.\n", hr);
     if (winetest_interactive) /* Timing problems make this test too liable to fail. */
-        ok(abs(current - 1334 * 10000) < 80 * 10000,
+        ok(compare_time(current, 1334 * 10000, 80 * 10000),
                 "Expected about 1334ms, got %s.\n", wine_dbgstr_longlong(current));
     ok(stop == 8000 * 10000, "Got time %s.\n", wine_dbgstr_longlong(stop));
 
@@ -4100,13 +4106,13 @@ static void test_graph_seeking(void)
     hr = IMediaSeeking_GetCurrentPosition(seeking, &time);
     ok(hr == S_OK, "Got hr %#x.\n", hr);
     if (winetest_interactive) /* Timing problems make this test too liable to fail. */
-        ok(abs(time - 1334 * 10000) < 80 * 10000,
+        ok(compare_time(time, 1334 * 10000, 80 * 10000),
                 "Expected about 1334ms, got %s.\n", wine_dbgstr_longlong(time));
     current = stop = 0xdeadbeef;
     hr = IMediaSeeking_GetPositions(seeking, &current, &stop);
     ok(hr == S_OK, "Got hr %#x.\n", hr);
     if (winetest_interactive) /* Timing problems make this test too liable to fail. */
-        ok(abs(current - 1334 * 10000) < 80 * 10000,
+        ok(compare_time(current, 1334 * 10000, 80 * 10000),
                 "Expected about 1334ms, got %s.\n", wine_dbgstr_longlong(current));
     ok(stop == 8000 * 10000, "Got time %s.\n", wine_dbgstr_longlong(stop));
 
diff --git a/dlls/quartz/tests/systemclock.c b/dlls/quartz/tests/systemclock.c
index b85a801f0ef..71a7ac26d84 100644
--- a/dlls/quartz/tests/systemclock.c
+++ b/dlls/quartz/tests/systemclock.c
@@ -24,6 +24,12 @@
 
 static ULONGLONG (WINAPI *pGetTickCount64)(void);
 
+static BOOL compare_time(REFERENCE_TIME x, REFERENCE_TIME y, unsigned int max_diff)
+{
+    REFERENCE_TIME diff = x > y ? x - y : y - x;
+    return diff <= max_diff;
+}
+
 static IReferenceClock *create_system_clock(void)
 {
     IReferenceClock *clock = NULL;
@@ -181,7 +187,7 @@ static void test_get_time(void)
     ok(hr == S_OK, "Got hr %#x.\n", hr);
     ok(time1 % 10000 == 0, "Expected no less than 1ms coarseness, but got time %s.\n",
             wine_dbgstr_longlong(time1));
-    ok(abs(time1 - time2) < 20 * 10000, "Expected about %s, got %s.\n",
+    ok(compare_time(time1, time2, 20 * 10000), "Expected about %s, got %s.\n",
             wine_dbgstr_longlong(time2), wine_dbgstr_longlong(time1));
 
     hr = IReferenceClock_GetTime(clock, &time2);
diff --git a/dlls/quartz/tests/vmr9.c b/dlls/quartz/tests/vmr9.c
index 2921d1aed02..7dd6dbe1dd2 100644
--- a/dlls/quartz/tests/vmr9.c
+++ b/dlls/quartz/tests/vmr9.c
@@ -73,18 +73,19 @@ static inline BOOL compare_media_types(const AM_MEDIA_TYPE *a, const AM_MEDIA_TY
 
 static BOOL compare_double(double f, double g, unsigned int ulps)
 {
-    int64_t x = *(int64_t *)&f;
-    int64_t y = *(int64_t *)&g;
+    uint64_t x = *(ULONGLONG *)&f;
+    uint64_t y = *(ULONGLONG *)&g;
 
-    if (x < 0)
-        x = INT64_MIN - x;
-    if (y < 0)
-        y = INT64_MIN - y;
+    if (f < 0)
+        x = ~x + 1;
+    else
+        x |= ((ULONGLONG)1)<<63;
+    if (g < 0)
+        y = ~y + 1;
+    else
+        y |= ((ULONGLONG)1)<<63;
 
-    if (abs(x - y) > ulps)
-        return FALSE;
-
-    return TRUE;
+    return (x>y ? x-y : y-x) <= ulps;
 }
 
 static IFilterGraph2 *create_graph(void)