diff --git a/src/core/corelib.c b/src/core/corelib.c
index 46a078e1..4b326496 100644
--- a/src/core/corelib.c
+++ b/src/core/corelib.c
@@ -1173,11 +1173,12 @@ JanetTable *janet_core_env(JanetTable *replacements) {
                           "the reciprocal of x. Otherwise return the first value of xs repeatedly divided by the remaining "
                           "values."));
     templatize_varop(env, JANET_FUN_MODULO, "mod", 0, 1, JOP_MODULO,
-                     JDOC("(mod dividend divisor)\n\n"
-                         "Returns the modulo of dividend / divisor."));
+                     JDOC("(mod & xs)\n\n"
+                         "Returns the result of applying the modulo operator on the first value of xs with each remaining value. "
+                         "`(mod x 0)` is defined to be `x`."));
     templatize_varop(env, JANET_FUN_REMAINDER, "%", 0, 1, JOP_REMAINDER,
-                     JDOC("(% dividend divisor)\n\n"
-                         "Returns the remainder of dividend / divisor."));
+                     JDOC("(% & xs)\n\n"
+                         "Returns the remainder of dividing the first value of xs by each remaining value."));
     templatize_varop(env, JANET_FUN_BAND, "band", -1, -1, JOP_BAND,
                      JDOC("(band & xs)\n\n"
                           "Returns the bit-wise and of all values in xs. Each x in xs must be an integer."));
diff --git a/src/core/inttypes.c b/src/core/inttypes.c
index 3910a866..c576e89d 100644
--- a/src/core/inttypes.c
+++ b/src/core/inttypes.c
@@ -431,7 +431,7 @@ static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
 } \
 
 #define OPMETHODINVERT(T, type, name, oper) \
-static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
+static Janet cfun_it_##type##_##name##i(int32_t argc, Janet *argv) { \
     janet_fixarity(argc, 2); \
     T *box = janet_abstract(&janet_##type##_type, sizeof(T)); \
     *box = janet_unwrap_##type(argv[1]); \
@@ -440,6 +440,11 @@ static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
     return janet_wrap_abstract(box); \
 } \
 
+#define DIVZERO(name) DIVZERO_##name
+#define DIVZERO_div janet_panic("division by zero")
+#define DIVZERO_rem janet_panic("division by zero")
+#define DIVZERO_mod return janet_wrap_abstract(box)
+
 #define DIVMETHOD(T, type, name, oper) \
 static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
     janet_arity(argc, 2, -1);                       \
@@ -447,19 +452,19 @@ static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
     *box = janet_unwrap_##type(argv[0]); \
     for (int32_t i = 1; i < argc; i++) { \
       T value = janet_unwrap_##type(argv[i]); \
-      if (value == 0) janet_panic("division by zero"); \
+      if (value == 0) DIVZERO(name); \
       *box oper##= value; \
     } \
     return janet_wrap_abstract(box); \
 } \
 
 #define DIVMETHODINVERT(T, type, name, oper) \
-static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
+static Janet cfun_it_##type##_##name##i(int32_t argc, Janet *argv) { \
     janet_fixarity(argc, 2);                       \
     T *box = janet_abstract(&janet_##type##_type, sizeof(T)); \
     *box = janet_unwrap_##type(argv[1]); \
     T value = janet_unwrap_##type(argv[0]); \
-    if (value == 0) janet_panic("division by zero"); \
+    if (value == 0) DIVZERO(name); \
     *box oper##= value; \
     return janet_wrap_abstract(box); \
 } \
@@ -471,7 +476,7 @@ static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
     *box = janet_unwrap_##type(argv[0]); \
     for (int32_t i = 1; i < argc; i++) { \
       T value = janet_unwrap_##type(argv[i]); \
-      if (value == 0) janet_panic("division by zero"); \
+      if (value == 0) DIVZERO(name); \
       if ((value == -1) && (*box == INT64_MIN)) janet_panic("INT64_MIN divided by -1"); \
       *box oper##= value; \
     } \
@@ -479,12 +484,12 @@ static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
 } \
 
 #define DIVMETHODINVERT_SIGNED(T, type, name, oper) \
-static Janet cfun_it_##type##_##name(int32_t argc, Janet *argv) { \
+static Janet cfun_it_##type##_##name##i(int32_t argc, Janet *argv) { \
     janet_fixarity(argc, 2);                       \
     T *box = janet_abstract(&janet_##type##_type, sizeof(T)); \
     *box = janet_unwrap_##type(argv[1]); \
     T value = janet_unwrap_##type(argv[0]); \
-    if (value == 0) janet_panic("division by zero"); \
+    if (value == 0) DIVZERO(name); \
     if ((value == -1) && (*box == INT64_MIN)) janet_panic("INT64_MIN divided by -1"); \
     *box oper##= value; \
     return janet_wrap_abstract(box); \
@@ -517,11 +522,12 @@ static Janet cfun_it_s64_mod(int32_t argc, Janet *argv) {
     int64_t *box = janet_abstract(&janet_s64_type, sizeof(int64_t));
     int64_t op1 = janet_unwrap_s64(argv[0]);
     int64_t op2 = janet_unwrap_s64(argv[1]);
-    if (op2 == 0) janet_panic("division by zero");
-    int64_t x = op1 % op2;
-    *box = (op1 > 0)
-           ? ((op2 > 0) ? x : (0 == x ? x : x + op2))
-           : ((op2 > 0) ? (0 == x ? x : x + op2) : x);
+    if (op2 == 0) {
+        *box = op1;
+    } else {
+        int64_t x = op1 % op2;
+        *box = (((op1 ^ op2) < 0) && (x != 0)) ? x + op2 : x;
+    }
     return janet_wrap_abstract(box);
 }
 
@@ -530,22 +536,23 @@ static Janet cfun_it_s64_modi(int32_t argc, Janet *argv) {
     int64_t *box = janet_abstract(&janet_s64_type, sizeof(int64_t));
     int64_t op2 = janet_unwrap_s64(argv[0]);
     int64_t op1 = janet_unwrap_s64(argv[1]);
-    if (op2 == 0) janet_panic("division by zero");
-    int64_t x = op1 % op2;
-    *box = (op1 > 0)
-           ? ((op2 > 0) ? x : (0 == x ? x : x + op2))
-           : ((op2 > 0) ? (0 == x ? x : x + op2) : x);
+    if (op2 == 0) {
+        *box = op1;
+    } else {
+        int64_t x = op1 % op2;
+        *box = (((op1 ^ op2) < 0) && (x != 0)) ? x + op2 : x;
+    }
     return janet_wrap_abstract(box);
 }
 
 OPMETHOD(int64_t, s64, add, +)
 OPMETHOD(int64_t, s64, sub, -)
-OPMETHODINVERT(int64_t, s64, subi, -)
+OPMETHODINVERT(int64_t, s64, sub, -)
 OPMETHOD(int64_t, s64, mul, *)
 DIVMETHOD_SIGNED(int64_t, s64, div, /)
 DIVMETHOD_SIGNED(int64_t, s64, rem, %)
-DIVMETHODINVERT_SIGNED(int64_t, s64, divi, /)
-DIVMETHODINVERT_SIGNED(int64_t, s64, remi, %)
+DIVMETHODINVERT_SIGNED(int64_t, s64, div, /)
+DIVMETHODINVERT_SIGNED(int64_t, s64, rem, %)
 OPMETHOD(int64_t, s64, and, &)
 OPMETHOD(int64_t, s64, or, |)
 OPMETHOD(int64_t, s64, xor, ^)
@@ -553,12 +560,14 @@ OPMETHOD(int64_t, s64, lshift, <<)
 OPMETHOD(int64_t, s64, rshift, >>)
 OPMETHOD(uint64_t, u64, add, +)
 OPMETHOD(uint64_t, u64, sub, -)
-OPMETHODINVERT(uint64_t, u64, subi, -)
+OPMETHODINVERT(uint64_t, u64, sub, -)
 OPMETHOD(uint64_t, u64, mul, *)
 DIVMETHOD(uint64_t, u64, div, /)
+DIVMETHOD(uint64_t, u64, rem, %)
 DIVMETHOD(uint64_t, u64, mod, %)
-DIVMETHODINVERT(uint64_t, u64, divi, /)
-DIVMETHODINVERT(uint64_t, u64, modi, %)
+DIVMETHODINVERT(uint64_t, u64, div, /)
+DIVMETHODINVERT(uint64_t, u64, rem, %)
+DIVMETHODINVERT(uint64_t, u64, mod, %)
 OPMETHOD(uint64_t, u64, and, &)
 OPMETHOD(uint64_t, u64, or, |)
 OPMETHOD(uint64_t, u64, xor, ^)
@@ -610,8 +619,8 @@ static JanetMethod it_u64_methods[] = {
     {"rdiv", cfun_it_u64_divi},
     {"mod", cfun_it_u64_mod},
     {"rmod", cfun_it_u64_modi},
-    {"%", cfun_it_u64_mod},
-    {"r%", cfun_it_u64_modi},
+    {"%", cfun_it_u64_rem},
+    {"r%", cfun_it_u64_remi},
     {"&", cfun_it_u64_and},
     {"r&", cfun_it_u64_and},
     {"|", cfun_it_u64_or},
diff --git a/src/core/vm.c b/src/core/vm.c
index e013fc78..cdc932ce 100644
--- a/src/core/vm.c
+++ b/src/core/vm.c
@@ -709,8 +709,12 @@ static JanetSignal run_vm(JanetFiber *fiber, Janet in) {
         if (janet_checktype(op1, JANET_NUMBER) && janet_checktype(op2, JANET_NUMBER)) {
             double x1 = janet_unwrap_number(op1);
             double x2 = janet_unwrap_number(op2);
-            double intres = x2 * floor(x1 / x2);
-            stack[A] = janet_wrap_number(x1 - intres);
+            if (x2 == 0) {
+              stack[A] = janet_wrap_number(x1);
+            } else {
+              double intres = x2 * floor(x1 / x2);
+              stack[A] = janet_wrap_number(x1 - intres);
+            }
             vm_pcnext();
         } else {
             vm_commit();