diff --git a/tests/include/test/helpers.h b/tests/include/test/helpers.h
index 689a1b5..564a553 100644
--- a/tests/include/test/helpers.h
+++ b/tests/include/test/helpers.h
@@ -61,14 +61,16 @@
     MBEDTLS_TEST_RESULT_SKIPPED
 } mbedtls_test_result_t;
 
+#define MBEDTLS_TEST_LINE_LENGTH 76
+
 typedef struct {
     mbedtls_test_result_t result;
     const char *test;
     const char *filename;
     int line_no;
     unsigned long step;
-    char line1[76];
-    char line2[76];
+    char line1[MBEDTLS_TEST_LINE_LENGTH];
+    char line2[MBEDTLS_TEST_LINE_LENGTH];
 #if defined(MBEDTLS_TEST_MUTEX_USAGE)
     const char *mutex_usage_error;
 #endif
diff --git a/tests/src/helpers.c b/tests/src/helpers.c
index 6bfe15d..52785fc 100644
--- a/tests/src/helpers.c
+++ b/tests/src/helpers.c
@@ -30,6 +30,15 @@
     return mbedtls_test_info.result;
 }
 
+void mbedtls_test_set_result(mbedtls_test_result_t result, const char *test,
+                             int line_no, const char *filename)
+{
+    mbedtls_test_info.result = result;
+    mbedtls_test_info.test = test;
+    mbedtls_test_info.line_no = line_no;
+    mbedtls_test_info.filename = filename;
+}
+
 const char *mbedtls_test_get_test(void)
 {
     return mbedtls_test_info.test;
@@ -54,15 +63,38 @@
     return mbedtls_test_info.step;
 }
 
+void mbedtls_test_set_step(unsigned long step) {
+    mbedtls_test_info.step = step;
+}
+
 const char *mbedtls_test_get_line1(void)
 {
     return mbedtls_test_info.line1;
 }
+
+void mbedtls_test_set_line1(const char *line)
+{
+    if (line == NULL) {
+        memset(mbedtls_test_info.line1, 0, sizeof(mbedtls_test_info.line1));
+    } else {
+        strncpy(mbedtls_test_info.line1, line, sizeof(mbedtls_test_info.line1));
+    }
+}
+
 const char *mbedtls_test_get_line2(void)
 {
     return mbedtls_test_info.line2;
 }
 
+void mbedtls_test_set_line2(const char *line) {
+    if (line == NULL) {
+        memset(mbedtls_test_info.line2, 0, sizeof(mbedtls_test_info.line2));
+    } else {
+        strncpy(mbedtls_test_info.line2, line, sizeof(mbedtls_test_info.line2));
+    }
+}
+
+
 #if defined(MBEDTLS_TEST_MUTEX_USAGE)
 const char *mbedtls_test_get_mutex_usage_error(void)
 {
@@ -126,28 +158,17 @@
 
 void mbedtls_test_fail(const char *test, int line_no, const char *filename)
 {
-    if (mbedtls_test_info.result == MBEDTLS_TEST_RESULT_FAILED) {
+    if (mbedtls_test_get_result() == MBEDTLS_TEST_RESULT_FAILED) {
         /* We've already recorded the test as having failed. Don't
          * overwrite any previous information about the failure. */
         return;
     }
-    mbedtls_test_info.result = MBEDTLS_TEST_RESULT_FAILED;
-    mbedtls_test_info.test = test;
-    mbedtls_test_info.line_no = line_no;
-    mbedtls_test_info.filename = filename;
+    mbedtls_test_set_result(MBEDTLS_TEST_RESULT_FAILED, test, line_no, filename);
 }
 
 void mbedtls_test_skip(const char *test, int line_no, const char *filename)
 {
-    mbedtls_test_info.result = MBEDTLS_TEST_RESULT_SKIPPED;
-    mbedtls_test_info.test = test;
-    mbedtls_test_info.line_no = line_no;
-    mbedtls_test_info.filename = filename;
-}
-
-void mbedtls_test_set_step(unsigned long step)
-{
-    mbedtls_test_info.step = step;
+    mbedtls_test_set_result(MBEDTLS_TEST_RESULT_SKIPPED, test, line_no, filename);
 }
 
 #if defined(MBEDTLS_BIGNUM_C)
@@ -156,13 +177,11 @@
 
 void mbedtls_test_info_reset(void)
 {
-    mbedtls_test_info.result = MBEDTLS_TEST_RESULT_SUCCESS;
-    mbedtls_test_info.step = (unsigned long) (-1);
-    mbedtls_test_info.test = 0;
-    mbedtls_test_info.line_no = 0;
-    mbedtls_test_info.filename = 0;
-    memset(mbedtls_test_info.line1, 0, sizeof(mbedtls_test_info.line1));
-    memset(mbedtls_test_info.line2, 0, sizeof(mbedtls_test_info.line2));
+    mbedtls_test_set_result(MBEDTLS_TEST_RESULT_SUCCESS, 0, 0, 0);
+    mbedtls_test_set_step((unsigned long) (-1));
+    mbedtls_test_set_line1(NULL);
+    mbedtls_test_set_line2(NULL);
+
 #if defined(MBEDTLS_BIGNUM_C)
     mbedtls_test_case_uses_negative_0 = 0;
 #endif
@@ -178,20 +197,21 @@
         return 1;
     }
 
-    if (mbedtls_test_info.result == MBEDTLS_TEST_RESULT_FAILED) {
+    if (mbedtls_test_get_result() == MBEDTLS_TEST_RESULT_FAILED) {
         /* We've already recorded the test as having failed. Don't
          * overwrite any previous information about the failure. */
         return 0;
     }
+    char buf[MBEDTLS_TEST_LINE_LENGTH];
     mbedtls_test_fail(test, line_no, filename);
-    (void) mbedtls_snprintf(mbedtls_test_info.line1,
-                            sizeof(mbedtls_test_info.line1),
+    (void) mbedtls_snprintf(buf, sizeof(buf),
                             "lhs = 0x%016llx = %lld",
                             value1, (long long) value1);
-    (void) mbedtls_snprintf(mbedtls_test_info.line2,
-                            sizeof(mbedtls_test_info.line2),
+    mbedtls_test_set_line1(buf);
+    (void) mbedtls_snprintf(buf, sizeof(buf),
                             "rhs = 0x%016llx = %lld",
                             value2, (long long) value2);
+    mbedtls_test_set_line2(buf);
     return 0;
 }
 
@@ -205,20 +225,21 @@
         return 1;
     }
 
-    if (mbedtls_test_info.result == MBEDTLS_TEST_RESULT_FAILED) {
+    if (mbedtls_test_get_result() == MBEDTLS_TEST_RESULT_FAILED) {
         /* We've already recorded the test as having failed. Don't
          * overwrite any previous information about the failure. */
         return 0;
     }
+    char buf[MBEDTLS_TEST_LINE_LENGTH];
     mbedtls_test_fail(test, line_no, filename);
-    (void) mbedtls_snprintf(mbedtls_test_info.line1,
-                            sizeof(mbedtls_test_info.line1),
+    (void) mbedtls_snprintf(buf, sizeof(buf),
                             "lhs = 0x%016llx = %llu",
                             value1, value1);
-    (void) mbedtls_snprintf(mbedtls_test_info.line2,
-                            sizeof(mbedtls_test_info.line2),
+    mbedtls_test_set_line1(buf);
+    (void) mbedtls_snprintf(buf, sizeof(buf),
                             "rhs = 0x%016llx = %llu",
                             value2, value2);
+    mbedtls_test_set_line2(buf);
     return 0;
 }
 
@@ -232,20 +253,21 @@
         return 1;
     }
 
-    if (mbedtls_test_info.result == MBEDTLS_TEST_RESULT_FAILED) {
+    if (mbedtls_test_get_result() == MBEDTLS_TEST_RESULT_FAILED) {
         /* We've already recorded the test as having failed. Don't
          * overwrite any previous information about the failure. */
         return 0;
     }
+    char buf[MBEDTLS_TEST_LINE_LENGTH];
     mbedtls_test_fail(test, line_no, filename);
-    (void) mbedtls_snprintf(mbedtls_test_info.line1,
-                            sizeof(mbedtls_test_info.line1),
+    (void) mbedtls_snprintf(buf, sizeof(buf),
                             "lhs = 0x%016llx = %lld",
                             (unsigned long long) value1, value1);
-    (void) mbedtls_snprintf(mbedtls_test_info.line2,
-                            sizeof(mbedtls_test_info.line2),
+    mbedtls_test_set_line1(buf);
+    (void) mbedtls_snprintf(buf, sizeof(buf),
                             "rhs = 0x%016llx = %lld",
                             (unsigned long long) value2, value2);
+    mbedtls_test_set_line2(buf);
     return 0;
 }