diff --git a/tests/suites/test_suite_constant_time.data b/tests/suites/test_suite_constant_time.data
index 82ee869..111fef6 100644
--- a/tests/suites/test_suite_constant_time.data
+++ b/tests/suites/test_suite_constant_time.data
@@ -646,6 +646,102 @@
 mbedtls_ct_if 0xffffffffffffffff 0xffffffffffffffff 0xffffffffffffffff
 mbedtls_ct_if:"0xffffffffffffffff":"0xffffffffffffffff":"0xffffffffffffffff"
 
+mbedtls_ct_error_if 0 0 0
+mbedtls_ct_error_if:0:0:0
+
+mbedtls_ct_error_if 0 0 -1
+mbedtls_ct_error_if:0:0:-1
+
+mbedtls_ct_error_if 0 0 -32766
+mbedtls_ct_error_if:0:0:-32766
+
+mbedtls_ct_error_if 0 0 -32767
+mbedtls_ct_error_if:0:0:-32767
+
+mbedtls_ct_error_if 0 -1 0
+mbedtls_ct_error_if:0:-1:0
+
+mbedtls_ct_error_if 0 -1 -1
+mbedtls_ct_error_if:0:-1:-1
+
+mbedtls_ct_error_if 0 -1 -32766
+mbedtls_ct_error_if:0:-1:-32766
+
+mbedtls_ct_error_if 0 -1 -32767
+mbedtls_ct_error_if:0:-1:-32767
+
+mbedtls_ct_error_if 0 -32766 0
+mbedtls_ct_error_if:0:-32766:0
+
+mbedtls_ct_error_if 0 -32766 -1
+mbedtls_ct_error_if:0:-32766:-1
+
+mbedtls_ct_error_if 0 -32766 -32766
+mbedtls_ct_error_if:0:-32766:-32766
+
+mbedtls_ct_error_if 0 -32766 -32767
+mbedtls_ct_error_if:0:-32766:-32767
+
+mbedtls_ct_error_if 0 -32767 0
+mbedtls_ct_error_if:0:-32767:0
+
+mbedtls_ct_error_if 0 -32767 -1
+mbedtls_ct_error_if:0:-32767:-1
+
+mbedtls_ct_error_if 0 -32767 -32766
+mbedtls_ct_error_if:0:-32767:-32766
+
+mbedtls_ct_error_if 0 -32767 -32767
+mbedtls_ct_error_if:0:-32767:-32767
+
+mbedtls_ct_error_if 1 0 0
+mbedtls_ct_error_if:1:0:0
+
+mbedtls_ct_error_if 1 0 -1
+mbedtls_ct_error_if:1:0:-1
+
+mbedtls_ct_error_if 1 0 -32766
+mbedtls_ct_error_if:1:0:-32766
+
+mbedtls_ct_error_if 1 0 -32767
+mbedtls_ct_error_if:1:0:-32767
+
+mbedtls_ct_error_if 1 -1 0
+mbedtls_ct_error_if:1:-1:0
+
+mbedtls_ct_error_if 1 -1 -1
+mbedtls_ct_error_if:1:-1:-1
+
+mbedtls_ct_error_if 1 -1 -32766
+mbedtls_ct_error_if:1:-1:-32766
+
+mbedtls_ct_error_if 1 -1 -32767
+mbedtls_ct_error_if:1:-1:-32767
+
+mbedtls_ct_error_if 1 -32766 0
+mbedtls_ct_error_if:1:-32766:0
+
+mbedtls_ct_error_if 1 -32766 -1
+mbedtls_ct_error_if:1:-32766:-1
+
+mbedtls_ct_error_if 1 -32766 -32766
+mbedtls_ct_error_if:1:-32766:-32766
+
+mbedtls_ct_error_if 1 -32766 -32767
+mbedtls_ct_error_if:1:-32766:-32767
+
+mbedtls_ct_error_if 1 -32767 0
+mbedtls_ct_error_if:1:-32767:0
+
+mbedtls_ct_error_if 1 -32767 -1
+mbedtls_ct_error_if:1:-32767:-1
+
+mbedtls_ct_error_if 1 -32767 -32766
+mbedtls_ct_error_if:1:-32767:-32766
+
+mbedtls_ct_error_if 1 -32767 -32767
+mbedtls_ct_error_if:1:-32767:-32767
+
 mbedtls_ct_zeroize_if 0x0 0
 mbedtls_ct_zeroize_if:"0x0":0
 
diff --git a/tests/suites/test_suite_constant_time.function b/tests/suites/test_suite_constant_time.function
index 3d5fa7f..b9a78c8 100644
--- a/tests/suites/test_suite_constant_time.function
+++ b/tests/suites/test_suite_constant_time.function
@@ -115,6 +115,27 @@
 /* END_CASE */
 
 /* BEGIN_CASE */
+void mbedtls_ct_error_if(int cond, int t, int f)
+{
+    mbedtls_ct_condition_t c = mbedtls_ct_bool(cond);
+
+    mbedtls_ct_uint_t expected = c ? t : f;
+    mbedtls_ct_uint_t expected0 = c ? t : 0;
+
+    TEST_CF_SECRET(&c, sizeof(c));
+    TEST_CF_SECRET(&t, sizeof(t));
+    TEST_CF_SECRET(&f, sizeof(f));
+
+    TEST_EQUAL(mbedtls_ct_error_if(c, t, f), expected);
+    TEST_EQUAL(mbedtls_ct_error_if_else_0(c, t), expected0);
+
+    TEST_CF_PUBLIC(&c, sizeof(c));
+    TEST_CF_PUBLIC(&t, sizeof(t));
+    TEST_CF_PUBLIC(&f, sizeof(f));
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
 void mbedtls_ct_if(char *c_str, char *t_str, char *f_str)
 {
     mbedtls_ct_condition_t c = mbedtls_ct_bool(strtoull(c_str, NULL, 16));