diff --git a/lib/timeval.c b/lib/timeval.c
index cb39308e0..2fd720144 100644
--- a/lib/timeval.c
+++ b/lib/timeval.c
@@ -120,8 +120,11 @@ long curlx_tvdiff(struct timeval newer, struct timeval older)
  */
 double curlx_tvdiff_secs(struct timeval newer, struct timeval older)
 {
-  return (double)(newer.tv_sec-older.tv_sec)+
-    (double)(newer.tv_usec-older.tv_usec)/1000000.0;
+  if(newer.tv_sec != older.tv_sec)
+    return (double)(newer.tv_sec-older.tv_sec)+
+      (double)(newer.tv_usec-older.tv_usec)/1000000.0;
+  else
+    return (double)(newer.tv_usec-older.tv_usec)/1000000.0;
 }
 
 /* return the number of seconds in the given input timeval struct */
diff --git a/src/tool_util.c b/src/tool_util.c
index 79c998295..93ab17fd4 100644
--- a/src/tool_util.c
+++ b/src/tool_util.c
@@ -123,8 +123,11 @@ long tool_tvdiff(struct timeval newer, struct timeval older)
  */
 double tool_tvdiff_secs(struct timeval newer, struct timeval older)
 {
-  return (double)(newer.tv_sec-older.tv_sec)+
-    (double)(newer.tv_usec-older.tv_usec)/1000000.0;
+  if(newer.tv_sec != older.tv_sec)
+    return (double)(newer.tv_sec-older.tv_sec)+
+      (double)(newer.tv_usec-older.tv_usec)/1000000.0;
+  else
+    return (double)(newer.tv_usec-older.tv_usec)/1000000.0;
 }
 
 /* return the number of seconds in the given input timeval struct */
diff --git a/tests/libtest/testutil.c b/tests/libtest/testutil.c
index 63393c589..4ee488e71 100644
--- a/tests/libtest/testutil.c
+++ b/tests/libtest/testutil.c
@@ -123,8 +123,11 @@ long tutil_tvdiff(struct timeval newer, struct timeval older)
  */
 double tutil_tvdiff_secs(struct timeval newer, struct timeval older)
 {
-  return (double)(newer.tv_sec-older.tv_sec)+
-    (double)(newer.tv_usec-older.tv_usec)/1000000.0;
+  if(newer.tv_sec != older.tv_sec)
+    return (double)(newer.tv_sec-older.tv_sec)+
+      (double)(newer.tv_usec-older.tv_usec)/1000000.0;
+  else
+    return (double)(newer.tv_usec-older.tv_usec)/1000000.0;
 }
 
 /* return the number of seconds in the given input timeval struct */