diff --git a/libtransmission/utils-test.c b/libtransmission/utils-test.c
index 110da07c7..8eabf2e40 100644
--- a/libtransmission/utils-test.c
+++ b/libtransmission/utils-test.c
@@ -414,6 +414,9 @@ static int test_truncd(void)
     tr_snprintf(buf, sizeof(buf), "%.0f", tr_truncd(3.3333, 0));
     check_str(buf, ==, "3");
 
+    tr_snprintf(buf, sizeof(buf), "%.0f", tr_truncd(3.9999, 0));
+    check_str(buf, ==, "3");
+
 #if !(defined(_MSC_VER) || (defined(__MINGW32__) && defined(__MSVCRT__)))
     /* FIXME: MSCVRT behaves differently in case of nan */
     tr_snprintf(buf, sizeof(buf), "%.2f", tr_truncd(nan, 2));
diff --git a/libtransmission/utils.c b/libtransmission/utils.c
index 42f4996ce..04b4372f7 100644
--- a/libtransmission/utils.c
+++ b/libtransmission/utils.c
@@ -17,9 +17,9 @@
 
 #include <ctype.h> /* isdigit(), tolower() */
 #include <errno.h>
-#include <float.h> /* DBL_EPSILON */
+#include <float.h> /* DBL_DIG */
 #include <locale.h> /* localeconv() */
-#include <math.h> /* pow(), fabs(), floor() */
+#include <math.h> /* fabs(), floor() */
 #include <stdio.h>
 #include <stdlib.h> /* getenv() */
 #include <string.h> /* strerror(), memset(), memmem() */
@@ -1625,8 +1625,7 @@ double tr_truncd(double x, int precision)
 {
     char* pt;
     char buf[128];
-    int const max_precision = (int)log10(1.0 / DBL_EPSILON) - 1;
-    tr_snprintf(buf, sizeof(buf), "%.*f", max_precision, x);
+    tr_snprintf(buf, sizeof(buf), "%.*f", DBL_DIG, x);
 
     if ((pt = strstr(buf, localeconv()->decimal_point)) != NULL)
     {