diff --git a/wolfcrypt/src/integer.c b/wolfcrypt/src/integer.c
index fe40dce89..3c86e665a 100644
--- a/wolfcrypt/src/integer.c
+++ b/wolfcrypt/src/integer.c
@@ -4717,10 +4717,15 @@ int mp_prime_is_prime (mp_int * a, int t, int *result)
     return MP_VAL;
   }
 
+  if (mp_isone(a)) {
+      *result = MP_NO;
+      return MP_OKAY;
+  }
+
   /* is the input equal to one of the primes in the table? */
   for (ix = 0; ix < PRIME_SIZE; ix++) {
       if (mp_cmp_d(a, ltm_prime_tab[ix]) == MP_EQ) {
-         *result = 1;
+         *result = MP_YES;
          return MP_OKAY;
       }
   }
@@ -4780,6 +4785,11 @@ int mp_prime_is_prime_ex (mp_int * a, int t, int *result, WC_RNG *rng)
     return MP_VAL;
   }
 
+  if (mp_isone(a)) {
+    *result = MP_NO;
+    return MP_OKAY;
+  }
+
   /* is the input equal to one of the primes in the table? */
   for (ix = 0; ix < PRIME_SIZE; ix++) {
       if (mp_cmp_d(a, ltm_prime_tab[ix]) == MP_EQ) {
diff --git a/wolfcrypt/src/sp_int.c b/wolfcrypt/src/sp_int.c
index 9e9b99530..422614e3d 100644
--- a/wolfcrypt/src/sp_int.c
+++ b/wolfcrypt/src/sp_int.c
@@ -1703,6 +1703,11 @@ int sp_prime_is_prime(sp_int *a, int t, int* result)
         err = MP_VAL;
     }
 
+    if (sp_isone(a)) {
+        *result = MP_NO;
+        return MP_OKAY;
+    }
+
     if (err == MP_OKAY && a->used == 1) {
         /* check against primes table */
         for (i = 0; i < SP_PRIME_SIZE; i++) {
@@ -1783,6 +1788,11 @@ int sp_prime_is_prime_ex(sp_int* a, int t, int* result, WC_RNG* rng)
     if (a == NULL || result == NULL || rng == NULL)
         err = MP_VAL;
 
+    if (sp_isone(a)) {
+        *result = MP_NO;
+        return MP_OKAY;
+    }
+
     if (err == MP_OKAY && a->used == 1) {
         /* check against primes table */
         for (i = 0; i < SP_PRIME_SIZE; i++) {
diff --git a/wolfcrypt/src/tfm.c b/wolfcrypt/src/tfm.c
index e2643b0f4..1f875d0cd 100644
--- a/wolfcrypt/src/tfm.c
+++ b/wolfcrypt/src/tfm.c
@@ -4096,6 +4096,11 @@ int fp_isprime_ex(fp_int *a, int t, int* result)
      return FP_VAL;
    }
 
+   if (fp_isone(a)) {
+       *result = FP_NO;
+       return FP_OKAY;
+   }
+
    /* check against primes table */
    for (r = 0; r < FP_PRIME_SIZE; r++) {
        if (fp_cmp_d(a, primes[r]) == FP_EQ) {
@@ -4146,6 +4151,11 @@ int mp_prime_is_prime_ex(mp_int* a, int t, int* result, WC_RNG* rng)
     if (a == NULL || result == NULL || rng == NULL)
         return FP_VAL;
 
+    if (fp_isone(a)) {
+        *result = FP_NO;
+        return FP_OKAY;
+    }
+
     if (ret == FP_YES) {
         fp_digit d;
         int r;
diff --git a/wolfcrypt/test/test.c b/wolfcrypt/test/test.c
index 54b9fe35c..0ebce4278 100644
--- a/wolfcrypt/test/test.c
+++ b/wolfcrypt/test/test.c
@@ -1080,7 +1080,7 @@ initDefaultName();
         test_pass("mp       test passed!\n");
 #endif
 
-#if defined(WOLFSSL_PUBLIC_MP) && !defined(WOLFSSL_SP_MATH)
+#if defined(WOLFSSL_PUBLIC_MP)
     if ( (ret = prime_test()) != 0)
         return err_sys("prime    test failed!\n", ret);
     else
@@ -24568,7 +24568,7 @@ done:
 #endif
 
 
-#if defined(WOLFSSL_PUBLIC_MP) && !defined(WOLFSSL_SP_MATH)
+#if defined(WOLFSSL_PUBLIC_MP)
 
 typedef struct pairs_t {
     const unsigned char* coeff;
@@ -24623,16 +24623,24 @@ static const unsigned char controlPrime[] = {
     0xe6, 0xd1, 0x1b, 0x5d, 0x5e, 0x96, 0xfa, 0x53
 };
 
+static const unsigned char testOne[] = { 1 };
+
 
 static int GenerateNextP(mp_int* p1, mp_int* p2, int k)
 {
     int ret;
+    mp_int ki;
 
-    ret = mp_sub_d(p1, 1, p2);
+    ret = mp_init(&ki);
     if (ret == 0)
-        ret = mp_mul_d(p2, k, p2);
+        ret = mp_set(&ki, k);
+    if (ret == 0)
+        ret = mp_sub_d(p1, 1, p2);
+    if (ret == 0)
+        ret = mp_mul(p2, &ki, p2);
     if (ret == 0)
         ret = mp_add_d(p2, 1, p2);
+    mp_clear(&ki);
 
     return ret;
 }
@@ -24738,6 +24746,23 @@ int prime_test(void)
     if (!isPrime)
         return -9661;
 
+    ret = mp_read_unsigned_bin(&n, testOne, sizeof(testOne));
+    if (ret != 0)
+        return -9662;
+
+    /* This test result should indicate the value as not prime. */
+    ret = mp_prime_is_prime_ex(&n, 8, &isPrime, &rng);
+    if (ret != 0)
+        return -9663;
+    if (isPrime)
+        return -9664;
+
+    ret = mp_prime_is_prime(&n, 8, &isPrime);
+    if (ret != 0)
+        return -9665;
+    if (isPrime)
+        return -9666;
+
     mp_clear(&p3);
     mp_clear(&p2);
     mp_clear(&p1);