diff --git a/bigWig.h b/bigWig.h
index dbfba02..88e1961 100644
--- a/bigWig.h
+++ b/bigWig.h
@@ -56,7 +56,7 @@ extern "C" {
 /*!
  * The library version number
  */
-#define LIBBIGWIG_VERSION 0.4.9
+#define LIBBIGWIG_VERSION 0.4.10
 
 /*!
  * If 1, then this library was compiled with remote file support.
diff --git a/bwWrite.c b/bwWrite.c
index d17d152..1a9c7a9 100644
--- a/bwWrite.c
+++ b/bwWrite.c
@@ -544,7 +544,7 @@ int bwAddIntervalSpanSteps(bigWigFile_t *fp, const char *chrom, uint32_t start,
         updateStats(fp, wb->span, values[i]);
         wb->l += 4;
     }
-    wb->end = wb->start + (wb->l>>2) * step;
+    wb->end = wb->start + ((wb->l-24)>>2) * step;
 
     return 0;
 }
@@ -567,7 +567,7 @@ int bwAppendIntervalSpanSteps(bigWigFile_t *fp, const float *values, uint32_t n)
         updateStats(fp, wb->span, values[i]);
         wb->l += 4;
     }
-    wb->end = wb->start + (wb->l>>2) * wb->step;
+    wb->end = wb->start + ((wb->l-24)>>2) * wb->step;
 
     return 0;
 }
diff --git a/io.c b/io.c
index 9b20b1a..96c0565 100644
--- a/io.c
+++ b/io.c
@@ -209,6 +209,11 @@ URL_t *urlOpen(const char *fname, CURLcode (*callBack)(CURL*), const char *mode)
                 fprintf(stderr, "[urlOpen] Failed instructing curl to use any HTTP authentication it finds to be suitable!\n");
                 goto error;
             }
+            // set user-agent
+            if(curl_easy_setopt(URL->x.curl, CURLOPT_USERAGENT, "libBigWig") != CURLE_OK) {
+                fprintf(stderr, "[urlOpen] Failed instructing curl to use libBigWig as a user-agent!\n");
+                goto error;
+            }
             //Follow redirects
             if(curl_easy_setopt(URL->x.curl, CURLOPT_FOLLOWLOCATION, 1L) != CURLE_OK) {
                 fprintf(stderr, "[urlOpen] Failed instructing curl to follow redirects!\n");
diff --git a/test/test.py b/test/test.py
index d79d32d..4a60516 100755
--- a/test/test.py
+++ b/test/test.py
@@ -42,7 +42,7 @@ def test_creation_from_scratch():
         assert p1 == 0
         with open(tmpout, mode="rb") as f:
             md5sum = hashlib.md5(f.read()).hexdigest()
-            assert md5sum == "ef104f198c6ce8310acc149d0377fc16"
+            assert md5sum == "c07d7b09a0e370f3caca50258c5a6957"
 
 
 def remote_test2():