diff --git a/CHANGELOG.md b/CHANGELOG.md
index 891782c6..1a29ff03 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 All notable changes to this project will be documented in this file.
 
 ## Unreleased
+- `string/` functions that take a pattern to search for will throw an error
+  when receiving the empty string.
 - Replace (start:end) style stacktrace source position information with
   line, column. This should be more readable for humans. Also, range information
   can be recovered by re-parsing source.
diff --git a/src/core/string.c b/src/core/string.c
index c02b2bc7..44f943e2 100644
--- a/src/core/string.c
+++ b/src/core/string.c
@@ -108,6 +108,9 @@ static void kmp_init(
     if (!lookup) {
         JANET_OUT_OF_MEMORY;
     }
+    if (patlen == 0) {
+        janet_panic("expected non-empty pattern");
+    }
     s->lookup = lookup;
     s->i = 0;
     s->j = 0;
@@ -378,15 +381,13 @@ static Janet cfun_string_split(int32_t argc, Janet *argv) {
     }
     findsetup(argc, argv, &state, 1);
     array = janet_array(0);
-    while ((result = kmp_next(&state)) >= 0 && limit--) {
+    while ((result = kmp_next(&state)) >= 0 && --limit) {
         const uint8_t *slice = janet_string(state.text + lastindex, result - lastindex);
         janet_array_push(array, janet_wrap_string(slice));
         lastindex = result + state.patlen;
     }
-    {
-        const uint8_t *slice = janet_string(state.text + lastindex, state.textlen - lastindex);
-        janet_array_push(array, janet_wrap_string(slice));
-    }
+    const uint8_t *slice = janet_string(state.text + lastindex, state.textlen - lastindex);
+    janet_array_push(array, janet_wrap_string(slice));
     kmp_deinit(&state);
     return janet_wrap_array(array);
 }
@@ -600,10 +601,12 @@ static const JanetReg string_cfuns[] = {
     },
     {
         "string/split", cfun_string_split,
-        JDOC("(string/split delim str)\n\n"
+        JDOC("(string/split delim str &opt start limit)\n\n"
              "Splits a string str with delimiter delim and returns an array of "
              "substrings. The substrings will not contain the delimiter delim. If delim "
-             "is not found, the returned array will have one element.")
+             "is not found, the returned array will have one element. Will start searching "
+             "for delim at the index start (if provided), and return up to a maximum "
+             "of limit results (if provided).")
     },
     {
         "string/check-set", cfun_string_checkset,
diff --git a/test/suite2.janet b/test/suite2.janet
index ed747348..c0428019 100644
--- a/test/suite2.janet
+++ b/test/suite2.janet
@@ -62,8 +62,7 @@
 
 # String functions
 (assert (= 3 (string/find "abc" "   abcdefghijklmnop")) "string/find 1")
-(assert (= nil (string/find "" "")) "string/find 2")
-(assert (= 0 (string/find "A" "A")) "string/find 3")
+(assert (= 0 (string/find "A" "A")) "string/find 2")
 (assert (string/has-prefix? "" "foo") "string/has-prefix? 1")
 (assert (string/has-prefix? "fo" "foo") "string/has-prefix? 2")
 (assert (not (string/has-prefix? "o" "foo")) "string/has-prefix? 3")
@@ -98,6 +97,12 @@
 (assert (deep= (string/find-all "e" "onetwothree") @[2 9 10]) "string/find-all 1")
 (assert (deep= (string/find-all "," "onetwothree") @[]) "string/find-all 2")
 
+(assert-error "string/find error 1" (string/find "" "abcd"))
+(assert-error "string/split error 1" (string/split "" "abcd"))
+(assert-error "string/replace error 1" (string/replace "" "." "abcd"))
+(assert-error "string/replace-all error 1" (string/replace-all "" "." "abcdabcd"))
+(assert-error "string/find-all error 1" (string/find-all "" "abcd"))
+
 # Check if abstract test works
 (assert (abstract? stdout) "abstract? stdout")
 (assert (abstract? stdin) "abstract? stdin")