diff --git a/NEWS b/NEWS
index e69ac155..7eebca04 100644
--- a/NEWS
+++ b/NEWS
@@ -1,6 +1,9 @@
 In Development:
 # Mentioning Check 0.10.0 for now, to fix distcheck target until next release
 
+* Emit only valid XML characters in XML logging (assumes ASCII encoding).
+  Bug #103
+
 * Add LGPL header to files where it was missing; update FSF address in LGPL headers
   Bug #110
 
diff --git a/src/check_print.c b/src/check_print.c
index d56e1707..35f13b64 100644
--- a/src/check_print.c
+++ b/src/check_print.c
@@ -95,34 +95,53 @@ static void srunner_fprint_results(FILE * file, SRunner * sr,
 
 void fprint_xml_esc(FILE * file, const char *str)
 {
+    /* The valid XML characters are as follows:
+     *   #x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF]
+     * Characters that are outside of ASCII must be encoded. Further, the
+     * following special characters:
+     *   " ' < > &
+     * must be encoded. We assume that the incoming string may be a multibyte
+     * character.
+     */
+
     for(; *str != '\0'; str++)
     {
+        char next = *str;
 
-        switch (*str)
+        /* handle special characters that must be escaped */
+        if(next == '"' || next == '\'' || next == '<' || next == '>' || next == '&')
         {
-
-                /* handle special characters that must be escaped */
-            case '"':
-                fputs("&quot;", file);
-                break;
-            case '\'':
-                fputs("&apos;", file);
-                break;
-            case '<':
-                fputs("&lt;", file);
-                break;
-            case '>':
-                fputs("&gt;", file);
-                break;
-            case '&':
-                fputs("&amp;", file);
-                break;
-
-                /* regular characters, print as is */
-            default:
-                fputc(*str, file);
-                break;
+            switch (next)
+            {
+                case '"':
+                    fputs("&quot;", file);
+                    break;
+                case '\'':
+                    fputs("&apos;", file);
+                    break;
+                case '<':
+                    fputs("&lt;", file);
+                    break;
+                case '>':
+                    fputs("&gt;", file);
+                    break;
+                case '&':
+                    fputs("&amp;", file);
+                    break;
+            }
+        }
+        /* printable ASCII */
+        else if(next >= ' ' && next <= '~')
+        {
+            fputc(next, file);
+        }
+        /* Non-printable character */
+        else if(next == 0x9 || next == 0xA || next == 0xD ||
+                next >= 0x20)
+        {
+            fprintf(file, "&#x%X;", next);
         }
+        /* If it did not get printed, it is not a valid XML character*/
     }
 }
 
diff --git a/tests/ex_output.c b/tests/ex_output.c
index 6d0aad27..9e4e7467 100644
--- a/tests/ex_output.c
+++ b/tests/ex_output.c
@@ -75,7 +75,7 @@ END_TEST
 
 START_TEST(test_xml_esc_fail_msg)
 {
-    ck_abort_msg("fail \" ' < > & message");
+    ck_abort_msg("fail \" ' < > & \x9 \xA" "X""\x08"" message"); /* backspace char \x08 deletes the X */
 }
 END_TEST
 
@@ -120,8 +120,8 @@ static Suite *make_xml_esc_suite(void)
     Suite *s;
     TCase *tc;
 
-    s = suite_create("XML escape \" ' < > & tests");
-    tc = tcase_create("description \" ' < > &");
+    s = suite_create("XML escape \" ' < > & \x9 \xA" "X""\x08"" tests"); /* backspace char \x08 deletes the X */
+    tc = tcase_create("description \" ' < > & \x9 \xA" "X""\x08"" end"); /* backspace char \x08 deletes the X */
     suite_add_tcase(s, tc);
 
     tcase_add_test(tc, test_xml_esc_fail_msg);
diff --git a/tests/test_output_strings b/tests/test_output_strings
index b23da03f..ccb3861f 100644
--- a/tests/test_output_strings
+++ b/tests/test_output_strings
@@ -2,12 +2,17 @@
 
 . ./test_vars
 
+# Set the 'internal field separator' character to
+# something besides whitespace so that the string
+# comparisons will work
+IFS="~"
+
 ##################
 # stdout output
 ##################
-suite_output="Running suite(s): S1
+suite_output=`printf "Running suite(s): S1
  S2
- XML escape \" ' < > & tests"
+ XML escape \" ' < > & \x9 \x0AX\x08 tests"`
 
 exp_silent=""
 
@@ -20,25 +25,25 @@ exp_minimal="$suite_output
 $exp_minimal_result"
 
 if [ $HAVE_FORK -eq 1 ]; then
-exp_normal_result="37%: Checks: 8, Failures: 4, Errors: 1
+exp_normal_result=`printf "37%%: Checks: 8, Failures: 4, Errors: 1
 ${SRCDIR}ex_output.c:37:F:Core:test_fail:0: Failure
 ${SRCDIR}ex_output.c:46:E:Core:test_exit:0: (after this point) Early exit with return value 1
 ${SRCDIR}ex_output.c:72:F:Core:test_loop:0: Iteration 0 failed
 ${SRCDIR}ex_output.c:72:F:Core:test_loop:2: Iteration 2 failed
-${SRCDIR}ex_output.c:78:F:description \" ' < > &:test_xml_esc_fail_msg:0: fail \" ' < > & message"
+${SRCDIR}ex_output.c:78:F:description \" ' < > & \x9 \x0AX\x08 end:test_xml_esc_fail_msg:0: fail \" ' < > & \x9 \x0AX\x08 message"`
 else
-exp_normal_result="42%: Checks: 7, Failures: 4, Errors: 0
+exp_normal_result=`printf "42%%: Checks: 7, Failures: 4, Errors: 0
 ${SRCDIR}ex_output.c:37:F:Core:test_fail:0: Failure
 ${SRCDIR}ex_output.c:72:F:Core:test_loop:0: Iteration 0 failed
 ${SRCDIR}ex_output.c:72:F:Core:test_loop:2: Iteration 2 failed
-${SRCDIR}ex_output.c:78:F:description \" ' < > &:test_xml_esc_fail_msg:0: fail \" ' < > & message"
+${SRCDIR}ex_output.c:78:F:description \" ' < > &\x9 \xA end:test_xml_esc_fail_msg:0: fail \" ' < > & \x9 \x0AX\x08 message"`
 fi
 exp_normal="$suite_output
 $exp_normal_result"
 
 
 if [ $HAVE_FORK -eq 1 ]; then
-exp_verbose_result="37%: Checks: 8, Failures: 4, Errors: 1
+exp_verbose_result=`printf "37%%: Checks: 8, Failures: 4, Errors: 1
 ${SRCDIR}ex_output.c:31:P:Core:test_pass:0: Passed
 ${SRCDIR}ex_output.c:37:F:Core:test_fail:0: Failure
 ${SRCDIR}ex_output.c:46:E:Core:test_exit:0: (after this point) Early exit with return value 1
@@ -46,22 +51,22 @@ ${SRCDIR}ex_output.c:66:P:Core:test_pass2:0: Passed
 ${SRCDIR}ex_output.c:72:F:Core:test_loop:0: Iteration 0 failed
 ${SRCDIR}ex_output.c:72:P:Core:test_loop:1: Passed
 ${SRCDIR}ex_output.c:72:F:Core:test_loop:2: Iteration 2 failed
-${SRCDIR}ex_output.c:78:F:description \" ' < > &:test_xml_esc_fail_msg:0: fail \" ' < > & message"
+${SRCDIR}ex_output.c:78:F:description \" ' < > & \x9 \x0AX\x08 end:test_xml_esc_fail_msg:0: fail \" ' < > & \x9 \x0AX\x08 message"`
 else
-exp_verbose_result="42%: Checks: 7, Failures: 4, Errors: 0
+exp_verbose_result=`printf "42%%: Checks: 7, Failures: 4, Errors: 0
 ${SRCDIR}ex_output.c:31:P:Core:test_pass:0: Passed
 ${SRCDIR}ex_output.c:37:F:Core:test_fail:0: Failure
 ${SRCDIR}ex_output.c:66:P:Core:test_pass2:0: Passed
 ${SRCDIR}ex_output.c:72:F:Core:test_loop:0: Iteration 0 failed
 ${SRCDIR}ex_output.c:72:P:Core:test_loop:1: Passed
 ${SRCDIR}ex_output.c:72:F:Core:test_loop:2: Iteration 2 failed
-${SRCDIR}ex_output.c:78:F:description \" ' < > &:test_xml_esc_fail_msg:0: fail \" ' < > & message"
+${SRCDIR}ex_output.c:78:F:description \" ' < > & \x9 \x0AX\x08 end:test_xml_esc_fail_msg:0: fail \" ' < > & \x9 \x0AX\x08 message"`
 fi
 exp_verbose="$suite_output
 $exp_verbose_result"
 
 if [ $HAVE_FORK -eq 1 ]; then
-exp_subunit="test: Core:test_pass
+exp_subunit=`printf "test: Core:test_pass
 success: Core:test_pass
 test: Core:test_fail
 failure: Core:test_fail [
@@ -83,12 +88,12 @@ test: Core:test_loop
 failure: Core:test_loop [
 ${SRCDIR}ex_output.c:72: Iteration 2 failed
 ]
-test: description \" ' < > &:test_xml_esc_fail_msg
-failure: description \" ' < > &:test_xml_esc_fail_msg [
-${SRCDIR}ex_output.c:78: fail \" ' < > & message
-]"
+test: description \" ' < > & \x9 \x0AX\x08 end:test_xml_esc_fail_msg
+failure: description \" ' < > & \x9 \x0AX\x08 end:test_xml_esc_fail_msg [
+${SRCDIR}ex_output.c:78: fail \" ' < > & \x9 \x0AX\x08 message
+]"`
 else
-exp_subunit="test: Core:test_pass
+exp_subunit=`printf "test: Core:test_pass
 success: Core:test_pass
 test: Core:test_fail
 failure: Core:test_fail [
@@ -106,17 +111,17 @@ test: Core:test_loop
 failure: Core:test_loop [
 ${SRCDIR}ex_output.c:72: Iteration 2 failed
 ]
-test: description \" ' < > &:test_xml_esc_fail_msg
-failure: description \" ' < > &:test_xml_esc_fail_msg [
-${SRCDIR}ex_output.c:78: fail \" ' < > & message
-]"
+test: description \" ' < > & \x9 \x0AX\x08 end:test_xml_esc_fail_msg
+failure: description \" ' < > & \x9 \x0AX\x08 end:test_xml_esc_fail_msg [
+${SRCDIR}ex_output.c:78: fail \" ' < > & \x9 \x0AX\x08 message
+]"`
 fi
 
 ##################
 # log output
 ##################
 if [ $HAVE_FORK -eq 1 ]; then
-expected_log_log="Running suite S1
+expected_log_log=`printf "Running suite S1
 ${SRCDIR}ex_output.c:31:P:Core:test_pass:0: Passed
 ${SRCDIR}ex_output.c:37:F:Core:test_fail:0: Failure
 ${SRCDIR}ex_output.c:46:E:Core:test_exit:0: (after this point) Early exit with return value 1
@@ -125,12 +130,12 @@ ${SRCDIR}ex_output.c:66:P:Core:test_pass2:0: Passed
 ${SRCDIR}ex_output.c:72:F:Core:test_loop:0: Iteration 0 failed
 ${SRCDIR}ex_output.c:72:P:Core:test_loop:1: Passed
 ${SRCDIR}ex_output.c:72:F:Core:test_loop:2: Iteration 2 failed
-Running suite XML escape \" ' < > & tests
-${SRCDIR}ex_output.c:78:F:description \" ' < > &:test_xml_esc_fail_msg:0: fail \" ' < > & message
+Running suite XML escape \" ' < > & \x9 \x0AX\x08 tests
+${SRCDIR}ex_output.c:78:F:description \" ' < > & \x9 \x0AX\x08 end:test_xml_esc_fail_msg:0: fail \" ' < > & \x9 \x0AX\x08 message
 Results for all suites run:
-37%: Checks: 8, Failures: 4, Errors: 1"
+37%%: Checks: 8, Failures: 4, Errors: 1"`
 else
-expected_log_log="Running suite S1
+expected_log_log=`printf "Running suite S1
 ${SRCDIR}ex_output.c:31:P:Core:test_pass:0: Passed
 ${SRCDIR}ex_output.c:37:F:Core:test_fail:0: Failure
 Running suite S2
@@ -138,10 +143,10 @@ ${SRCDIR}ex_output.c:66:P:Core:test_pass2:0: Passed
 ${SRCDIR}ex_output.c:72:F:Core:test_loop:0: Iteration 0 failed
 ${SRCDIR}ex_output.c:72:P:Core:test_loop:1: Passed
 ${SRCDIR}ex_output.c:72:F:Core:test_loop:2: Iteration 2 failed
-Running suite XML escape \" ' < > & tests
-${SRCDIR}ex_output.c:78:F:description \" ' < > &:test_xml_esc_fail_msg:0: fail \" ' < > & message
+Running suite XML escape \" ' < > & \x9 \x0AX\x08 tests
+${SRCDIR}ex_output.c:78:F:description \" ' < > & \x9 \x0AX\x08 end:test_xml_esc_fail_msg:0: fail \" ' < > & \x9 \x0AX\x08 message
 Results for all suites run:
-42%: Checks: 7, Failures: 4, Errors: 0"
+42%%: Checks: 7, Failures: 4, Errors: 0"`
 fi
 
 ##################
@@ -207,19 +212,19 @@ expected_xml="<?xml version=\"1.0\"?>
     </test>
   </suite>
   <suite>
-    <title>XML escape &quot; &apos; &lt; &gt; &amp; tests</title>
+    <title>XML escape &quot; &apos; &lt; &gt; &amp; &#x9; &#xA;X tests</title>
     <test result=\"failure\">
       <fn>ex_output.c:78</fn>
       <id>test_xml_esc_fail_msg</id>
       <iteration>0</iteration>
-      <description>description &quot; &apos; &lt; &gt; &amp;</description>
-      <message>fail &quot; &apos; &lt; &gt; &amp; message</message>
+      <description>description &quot; &apos; &lt; &gt; &amp; &#x9; &#xA;X end</description>
+      <message>fail &quot; &apos; &lt; &gt; &amp; &#x9; &#xA;X message</message>
     </test>
   </suite>
 </testsuites>"
 expected_duration_count=9
 else
-expected_xml="<?xml version=\"1.0\"?>
+expected_xml="<?xml version=\"1.0\" encoding=\"UTF-8\"?>
 <?xml-stylesheet type=\"text/xsl\" href=\"http://check.sourceforge.net/xml/check_unittest.xslt\"?>
 <testsuites xmlns=\"http://check.sourceforge.net/ns\">
   <suite>
@@ -271,13 +276,13 @@ expected_xml="<?xml version=\"1.0\"?>
     </test>
   </suite>
   <suite>
-    <title>XML escape &quot; &apos; &lt; &gt; &amp; tests</title>
+    <title>XML escape &quot; &apos; &lt; &gt; &amp; &#x9; &#xA;X tests</title>
     <test result=\"failure\">
       <fn>ex_output.c:78</fn>
       <id>test_xml_esc_fail_msg</id>
       <iteration>0</iteration>
-      <description>description &quot; &apos; &lt; &gt; &amp;</description>
-      <message>fail &quot; &apos; &lt; &gt; &amp; message</message>
+      <description>description &quot; &apos; &lt; &gt; &amp; &#x9; &#xA;X end</description>
+      <message>fail &quot; &apos; &lt; &gt; &amp; &#x9; &#xA;X message</message>
     </test>
   </suite>
 </testsuites>"
@@ -288,16 +293,16 @@ fi
 # tap output
 ##################
 if [ $HAVE_FORK -eq 1 ]; then
-expected_normal_tap="ok 1 - ${SRCDIR}ex_output.c:Core:test_pass: Passed
+expected_normal_tap=`printf "ok 1 - ${SRCDIR}ex_output.c:Core:test_pass: Passed
 not ok 2 - ${SRCDIR}ex_output.c:Core:test_fail: Failure
 not ok 3 - ${SRCDIR}ex_output.c:Core:test_exit: Early exit with return value 1
 ok 4 - ${SRCDIR}ex_output.c:Core:test_pass2: Passed
 not ok 5 - ${SRCDIR}ex_output.c:Core:test_loop: Iteration 0 failed
 ok 6 - ${SRCDIR}ex_output.c:Core:test_loop: Passed
 not ok 7 - ${SRCDIR}ex_output.c:Core:test_loop: Iteration 2 failed
-not ok 8 - ${SRCDIR}ex_output.c:description \" ' < > &:test_xml_esc_fail_msg: fail \" ' < > & message
-1..8"
-expected_aborted_tap="ok 1 - ${SRCDIR}ex_output.c:Core:test_pass: Passed
+not ok 8 - ${SRCDIR}ex_output.c:description \" ' < > & \x9 \x0AX\x08 end:test_xml_esc_fail_msg: fail \" ' < > & \x9 \x0AX\x08 message
+1..8"`
+expected_aborted_tap=`printf "ok 1 - ${SRCDIR}ex_output.c:Core:test_pass: Passed
 not ok 2 - ${SRCDIR}ex_output.c:Core:test_fail: Failure
 not ok 3 - ${SRCDIR}ex_output.c:Core:test_exit: Early exit with return value 1
 not ok 4 - ${SRCDIR}ex_output.c:Core:test_abort: Early exit with return value 1
@@ -305,17 +310,17 @@ ok 5 - ${SRCDIR}ex_output.c:Core:test_pass2: Passed
 not ok 6 - ${SRCDIR}ex_output.c:Core:test_loop: Iteration 0 failed
 ok 7 - ${SRCDIR}ex_output.c:Core:test_loop: Passed
 not ok 8 - ${SRCDIR}ex_output.c:Core:test_loop: Iteration 2 failed
-not ok 9 - ${SRCDIR}ex_output.c:description \" ' < > &:test_xml_esc_fail_msg: fail \" ' < > & message
-1..9"
+not ok 9 - ${SRCDIR}ex_output.c:description \" ' < > & \x9 \x0AX\x08 end:test_xml_esc_fail_msg: fail \" ' < > & \x9 \x0AX\x08 message
+1..9"`
 else
-expected_normal_tap="ok 1 - ${SRCDIR}ex_output.c:Core:test_pass: Passed
+expected_normal_tap=`printf "ok 1 - ${SRCDIR}ex_output.c:Core:test_pass: Passed
 not ok 2 - ${SRCDIR}ex_output.c:Core:test_fail: Failure
 ok 3 - ${SRCDIR}ex_output.c:Core:test_pass2: Passed
 not ok 4 - ${SRCDIR}ex_output.c:Core:test_loop: Iteration 0 failed
 ok 5 - ${SRCDIR}ex_output.c:Core:test_loop: Passed
 not ok 6 - ${SRCDIR}ex_output.c:Core:test_loop: Iteration 2 failed
-not ok 7 - ${SRCDIR}ex_output.c:description \" ' < > &:test_xml_esc_fail_msg: fail \" ' < > & message
-1..7"
+not ok 7 - ${SRCDIR}ex_output.c:description \" ' < > & \x9 \x0AX\x08 end:test_xml_esc_fail_msg: fail \" ' < > & \x9 \x0AX\x08 message
+1..7"`
 # When fork() is unavailable, one of the tests
 # will invoke exit() which will terminate the
 # unit testing program. In that case, the tap
diff --git a/tests/test_xml_output.sh b/tests/test_xml_output.sh
index 7497f376..11bb77ad 100755
--- a/tests/test_xml_output.sh
+++ b/tests/test_xml_output.sh
@@ -25,12 +25,18 @@ if [ x"${expected_duration_count}" != x"${actual_duration_count}" ]; then
     exit 1;
 fi
 
-for duration in `grep "\<duration\>" ${OUTPUT_FILE} | cut -d ">" -f 2 | cut -d "<" -f 1`; do
-int_duration=`echo $duration | cut -d "." -f 1`
-if [ "${int_duration}" -ne "-1" ] && [ "${int_duration}" -gt "${CK_DEFAULT_TIMEOUT}" ]; then
-    echo "Problem with duration ${duration}; is not valid. Should be -1 or in [0, ${CK_DEFAULT_TIMEOUT}]"
-    exit 1
-fi
+num_durations=`grep "\<duration\>" ${OUTPUT_FILE} | wc -l`
+
+i=1
+while [ ${i} -le ${num_durations} ]; do
+   duration=`grep "\<duration\>" ${OUTPUT_FILE} | head -n ${i} | tail -n 1 | cut -d ">" -f 2 | cut -d "<" -f 1`
+   int_duration=`echo $duration | cut -d "." -f 1`
+   if [ "${int_duration}" -ne "-1" ] && [ "${int_duration}" -gt "${CK_DEFAULT_TIMEOUT}" ]; then
+       echo "Problem with duration ${duration}; is not valid. Should be -1 or in [0, ${CK_DEFAULT_TIMEOUT}]"
+       exit 1
+   fi
+
+   i=$((i+1))
 done